Some time ago, I started playing Nidalee. I was desperate for a new champ, since my old main, Mordekaiser, became less OP.
What I found out soon was that Nidalee is an awesome champion!

The way I play Nidalee is with full AP, nothing more, nothing less. I couldn't really find builds like this here, so i decided to make one of my own.

I apologize in advance for any grammatical errors, English is not my native language.

My Runes are fully AP. I used to have movement speed quintessences and cooldown reduction runes, but nidalee is pretty fast in cougar form, especially while in brushes, and with my build I'll have full cooldown reduction anyway.

Other rune possibilities would be armor/magic penetration. I wouldn't go for HP quintessences with this build, because I usually stand in the back, throwing spears and healing others.

For Summoner Spells I always use Flash and Ignite.

Flash is great to use for chasing or running away. For chasing I usually go

• Pounce + Javelin Toss
• Flash + Pounce + Swipe + Takedown (if close enough)
• Flash + Pounce + Javelin Toss (if too far away)

I assume you know the tricks of running away with flash, otherwise I'm sure there are plenty of builds that explains you how to. Notice that you can actually jump over some walls with Pounce, but you have to make a perfect jump. I'll try to see if I can find a way to make it clearer for you how to do that.

As for ignite, it is just a great ability to get that last bit of damage to kill your opponent.

I have chosen the bonusses for both my summoner spells. Also I have picked the extra starting gold, which is usefull for buying a health or mana potion, like you could earlier, before the Doran's Items got more expensive.
I believe the other mastery points are pretty logical. I have decided not to choose the spell vamp, because it won't help much for Nidalee and she has her own heal anyway.

When it comes to upgrading your skills, I always start with Javelin Toss/Takedown. Most people use Bushwhack/Pounce as first skill to get map controll, but in my opinion you can use your spear for that as well, giving enemy champions waiting in a brush even more damage than with your Bushwhack. As for the mana it costs, I usually get it fully regenerated back after using it to secure brushes, before the minions arrive.

After that it's pretty simple. I try and max my Javelin Toss/Takedown as soon as possible, choosing Primal Surge/Swipe as second, but making sure I have Bushwhack/Pounce before i get to lvl 6, because Pounce is a vital skill for her when in Cougar form.
If the enemy team has a Jungler, I usually get my Bushwhack/Pounce at lvl 3 to make sure i won't get ganked early game.

If you think your team needs you for your Primal Surge, you can max that one first, though I actually never do that, I love my spear too much!

The Items I use are

• Ionian Boots of Lucidity
• Rabadon's Deathcap
• Morello's evil Tome
• Lich Bane
• Void Staff

Usually I don't even have the time to buy these Items because the games finish kinda quickly these days. Ofcourse the games end in a victory for us! ;)
When I do get this oppurtonity, I just try and get more AP, wich means I try and go for another Rabadon's.

Why?

I use the Boots of Lucidity for the cooldown reduction, so I don't have to use runes for that. Along with Morello's Evil Tome I have max cooldown reduction, still a decent amount of AP and some mana regen as well.
Rabadon's Deathcap is a must-have for every champion that goes full AP. The amount of AP you get is epic.
Lich Bane is what I decided to use after I read some other builds and looked at the item closely. This Item gives mana, ap, movement speed and even some magic resist. Considering this item also has an increadible passive, this is a decent item for Nidalee.
I added Void Staff after I got that advice from the comments. Thinking about it, I have no idea why I didn't use this item earlier. I had no magic penetration before, therefore this item seems like a must-have.

Other Items You Could Use

A good item for Nidalee is Mejai's Soulstealer, if you are absolutely certain that you won't get caught. To be honest I am not sure why I don't use this item, but I'm satisfied with the items I use and these Items have no risks.

Another Possibility is Archangel's Staff, but personally I think it takes just too much time to build this item and gives too little AP early game.

Rod of Ages is a similar item. It's cool once fully stacked, but that takes a while.

Early Game

I start off with a Doran's Ring.
You could go for an Amplifyng Tome and Heal Potion, but since you have a heal of your own, I wouldn't think it's necessary.
Other items I used to start with would be a Meki Pendant and heal potions so you can build for a Tear of the Godess that would grow into an Archangel's Staff, but like I said I think that it takes too much time.

After that I usually get enough money to go for Blasting Wand and Boots of Speed. If you can't manage to get enough money for that, you can also get an Amplifying Tome instead of the Blasting Wand, you will need it for the Morello's Evil Tome or Lich Bane anyway.

I always try to get enough money to buy a Needlessly Large Rod and Ionian Boots of Lucidity. Most of the time I realise I will not be able to do that in time, so I'll buy the Fiendish Codex first , along with the Ionian Boots of Lucidity. After that I always go for the Rabadon's Deathcap otherwise it will be too late.

Mid Game

When I have Rabadon's Deathcap and Fiendish Codex, I go for Morello's Evli Tome and Lich Bane.
I'll try and see when it is the best time to buy the Void Staff. When I know that i'll let you know.

Pros:

• Good in chasing/escaping
• Great range
• Decent map awareness
• High Damage Spear (Javelin Toss)
• Massive heal (Primal Surge)
• Ultimate gives you 3 new no-cost-abilities which do a lot damage as well

Cons:

• Very Squishy; I noticed you can usually handle 1 stun but when you get more stuns or slows you're dead
• It's hard to 1v1
• Pounce is hard to master; she doesn't jump towards your mouse but to which direction she stands in
• Javelin Throw is hard to master
• Her heal has a tiny delay in my opinion.

This is my first build ever. I don't know the tricks of how to insert images or items in the chapter, so I used the colours to try and make things a bit clearer for you.
I hope this build is worth something for you guys, I can have a lot of fun with it.

The last item is really yours to decide. Personally I don't use items with an active, because I know I'll never use it. I try to avoid items that stack, because I con't like taking risks.

Please vote and comment, we can all learn something from it. If you have a valuable tip or if Nidalee gets nerfed/buffed, I'll try to update my build.

Good Luck!