Hello there, welcome to the first of many guides I have lined up. In this guide though I will be focusing on the AD side of Nidalee and all her feline wonders.

[*]General Info

To be quite plain, Nidalee is a versatile champion able to fill many roles in the current "meta". Her passive allows her to travel through bushes at an increased rate and lasts 2 seconds after she leaves a bush. Her skills include a base four moves as well as an alternate three through her ultimate.
Javelin Toss/Takedown

Human - (Skill Shot) Nidalee tosses her Javelin dealing damage (+65% of AP). The damage increases the further away you are from the target hit. (up to 250% extra damage)

Cougar - (On Hit) Nidalee's next attack deals damage (+100% of AD) to an enemy dealing bonus damage if the enemy is low on health. (up to 300% extra damage)
Bushwhack/Pounce

Human - Nidalee lays a trap that when triggered deals damage, reduces resistances, and reveals the enemy for a short time. (can hit multiple enemies and can be triggered by creeps)

Cougar - Nidalee pounces a short distance dealing AoE damage in the area she lands. (Can be used to jump over small walls)
Primal Surge/Swipe

Human - Heals an ally champion (+70% of AP) and increases their attack speed by 60% for 7 seconds.

Cougar - Nidalee swipes in the area in front of her dealing magic damage to enemies (+40% AP)
Aspect of The Cougar

Nidalee transforms into a cougar gaining the abilities Takedown, Pounce, and Swipe as well as increasing her resistances and movement speed slightly. (Nidalee becomes a melee champion in cougar form)
Re-toggle to become a human once again.

Marks:
Greater Mark of Strength x9 (Attack Damage) Masteries give flat damage an edge over ArmPen.

Seals:
Greater Seal of Clarity x9 (Mana Regen) Nidalee's spell early game cost a TON of mana, this is to combat that issue.
Can also use Greater Seal of Celerity for some cooldown reduction.

Glyphs:
Greater Glyph of Shielding x9 (Magic Resist) Just like any melee champion, you will be targeted by the enemy AP Carry and will take you more time to get to him than it will take him to get to you.
Greater Glyph of Warding can be used for more early game MR but fall off at level 11

Quintessences
Greater Quintessence of Strength x1 (Attack Damage) Again, masteries give the edge to flat damage runes.
Greater Quintessence of Swiftness x2 (Movement Speed) Nidalee has some insane chase and escape, this is to help that along.
Although I personally enjoy the move speed of Swiftness swapping one extra Quintessence for another Strength Quintessence is perfectly fine.

21-0-9 is the best set of masteries I could possibly think of. Some players enjoy a more defensive build such as 15-6-10 taking the MR and Armor for the defensive tree but it is simply not worth all the damage lost.

I chose

[*]Tips and Tricks

Blue is the single most important thing for Nidalee early-mid game. If your jungler doesn't need it, take it every time.

Nidalee's pounce can be used to jump over small walls. (if you can attack over it you can pretty much jump over it.

Try to land a spear and heal just before you cougar form and pounce in. This will give you maximum damage.

Bushwhack can be used to clear bushes without face-checking and can give you fair warning until you can afford wards.

Other Champs are scared of Nidalee's spear, and for good reason. They will hide behind creeps and move around them if you try to get a good angle. The best way to combat this is to stay behind the creeps yourself and throw spears through recently dead minions. As a minion is killed they leave a gap in the minion wall. Your opponent sees this as safe but, unfortunately for him, it is not. Use this to your advantage.

Another trick to land Nidalee's spear it to lead your opponent. Simply throw the spear in front of them, where they will be running in about a second or so. If it does not hit then they have turned around and now face your pounce and claws.

The last way to ensure you hit with Nidalee's spear is to hide in bushes, over walls or, just generally out of sight. Nidalee's spear has an incredible range and because of this she is deadly even when you cannot see her. If the enemy is camping out at his turret, run through the forest and lob a spear through the wall at him. Either he'll move or he'll die.

Bushwhack reduces resistances. By throwing it down in front of or just behind your opponent before you engage each other it will give you a massive advantage.

While supporting, try to heal your highest auto attack damage dealer just before you engage. This will turn them into the right click mini-gun they want to be.

(more tips to come)

Generally, any character with a slow, snare, or stun is dangerous to Nidalee. I.E.

Taric - Stun
Morgana - Snare
Kayle - Slow
Janna - Slow, Knock-up
Sona - Stun
Sion - Stun
Alistar - Stun, Knock-up, Knock-back
Annie - Stun
Amumu - Stun x2
Anivia - Stun, Slow
Ashe - Stun, Slow (for days)
Brand - Stun (easier to dodge)
Kennen - Stun
Vayne - Stun (position dependent)
Sejuani - Slow, Stun
Skarner - Drag
Tryndamere - Slow (massive early game dominance)
Cho'Gath - Slow, Knock-up, Silence
Maokai - Stun, Knock-back
Fizz - Knock-up, Slow
Warwick - Suppress

The three main characters to watch out for in all three builds are Sion, Soraka, and Tryndamere.

Sion - With his superior health and stun, Sion tends to dominate Nidalee even under her tower. The trick playing against Sion is to poke him with your spear as much as possible and to get frequent ganks from your jungle.

Soraka - Soraka is not a big threat early game and I know she was not on the list above but, once her q reaches level 2 her MR shred can completely open you up to enemy AP carries that you would otherwise destroy. Her silence is also huge as it stops you from pouncing away from danger.

Tryndamere - Most players use Crit runes for early game as Trynd and as such like to play a bit more aggresive. Due to Nidalee's relative low HP early game, this is a huge danger to you. There is good news though, you are ranged, he is melee. Harass him from afar whenever he tries to get a creep. This should keep him on his toes until level 6. Once he hits level six, be prepared to be dove upon. That Trynd can 3 shot you and he knows it. Have a heal ready and be prepared to duck and weave. Fortunately, him diving forces him to use his Ultimate and you have Ignite. If you can survive the dive and his ult goes up, wait just a moment and ignite him as he runs. Profit. Late game, you are best off ignoring Trynd and focus on his squishier, less invisible carries. He will focus you, and you can normally take the hit late game. Just be careful to not stay too long or he'll get lucky, crit you, and end up with a smile.

Explination of skill order

Here's a short explanation as to why certain skills are maxed over others. First, Primal Surge is maxed first because, as a bruiser you will be aiming to do as much damage as you can in a short period of time. Throwdown has relatively low damage unless you are going up against a weak opponent. You will also be hurt as well but, don't worry. Primal Surge is the answer to both those issues. Use it on yourself and pounce in. You will attack extremely fast and do considerable damage. Once you have done your deed the enemy will likely return the favor. Simply pounce out, heal and you have successfully hurt them and come out rather unscathed.

While Throwdown is weaker than Primal Surge as far as usefullness, it still has much more damage than Pounce. Since Pounce's distance does not change with level leaving it at level 1 is perfectly fine.

The reasoning behind taking Bushwhack at level 2 instead of Javelin is this. Recent META has begun calling for early ganks from fast jungles. Since Nid has relatively low early game damage it is easy to harass here before level 6 and allow a fast ganker to take advantage of weak moments in her laning phase. You can combat this with wards obviously but 90% of the time you wont have the gold or the chance to ward for yourself and neither will your jungle buddy. That is where Bushwhack comes in.

Summoner's Spells

For this build you want to use. Ignite and Flash as your main choices. You may use Exhaust or Cleanse in place of Ignite for situations where your team has 2-3 Ignites already or the enemy team is full of CC respectively.

The Build

Start withBoots of Speed,Health Potion x2, andMana Potion x1

From here you want to build into eitherGiant's Belt orPhage (with the intention of building either aTrinity Force orFrozen Mallet)

At this point you can go one of two ways. Beefy or flat damage.

For a beefier build buy a Giant's Belt and finish off yourNinja Tabi andTrinity Force. Then turn you Giant's Belt into aWarmog's Armor, grab aForce of Nature.

The last item is very dependent on the enemy team. You don't need any more defense at this point but your damage may lack a bit.
For armor heavy enemies finish with aLast Whisper.
If you find that your enemies lack armor finish aYoumuu's Ghostblade.

This is a work in progress. I am open to questions and suggestions as long as they are constructive.