I started playing for Nidalee 10 months ago, so I got much of experience. First, I want to tell you about Nidalee. Armor penetration Nidalee is early/mid game dominator, and magic penetration Nidalee is mid/lategame dominator. Well, I know that a lot of guys( not skilled) say that Nidalee is supposed to be a support,although it is not true, her skills are to dominate her lane and of course be very useful in teamfights.

P.S. This guide will include a lot of information from HotshotGG's guide, but he didn't write some very important information such as situational items. So please don't say that it is just a fake.

It's simple, I won't tell you something about Offensive or Defensive trees only about Utility tree. Nidalee realy needs blue buff so i upped "Utility Mastery" to 2. Nidalee has to stay in solo lane and she is a great dominator as I said before, so I got "Awareness". Using Cooldown Reduction runes is not correct, because you can get something more usefull, so I got Cooldown Reduction masteries. And I got "Meditation" for more mana regen. If you got more mana regeneration you can heal yourself more. Healing yourself= more lane domination.

I have chosen that runes for armor penetration Nidalee because you have to penetrate your opponent's armor.
Examples of high sarmor solo champions:
Jarvan IV, Rumble, Renekton, Cho'gath, Irelia, Jax, Singed, Udyr, Lee Sin.
Vs them you have to use Armor pen. rune setup.
Examples of low armor solo champions:
Akali, Gangplank, Vlad, Kennen, Kassadin, AP Gragas.
Vs these champions you have to use magic. pen rune setup.

Armor Seals help you in early game very much. Magic resistance Glyphs help you mid/early game very much aswell.
Ap per lvl Glyphs for Magic pen. Nidalee help you to dominate lane with your E in human stance.

Ghost helps to catch up your enemy and destroy him. Flash helps you get away from ganks, kill your opponent in that time when he doesn't expect it from you, run away from teamfights with low hp.

Leveling heal first takes priority over pre-trapping. You lose too much lane sustainability without it. Only level spear over primal surge if it will be 100% nice skillshot!!!!!

Nidalee is a nice farmer and can dominate her solo lane aswell. During the laning phase you should always prioritize last hits over harassment! If you are good Nidalee player you have to find time for the both (harrasing and last hitting). At level six always make sure you are near max health when you engage the enemy, keep pressure and take out your opponent in cougar form. Make sure your mana is not always FULL, IS NOT!!! You have to use
"Primal Surge" many times! And if you can see a lot of creeps near enemy make sure you have enough mana for heal, and then you can harras him. Don't use "Javelin Toss" in early levels.

Be carefull with these junglers: Nunu and Trundle, they are very dangerous junglers, who can gank before lvl 6.

Upper you can see my item build. Yes, it's nice, it works very well. However, there are situational items.- Very nice item if in your lane very agressive/non mana champion. Nice to use it against: Akali, Morderkaiser, Udyr, Vlad, agressive Cho'gath and against Lee Sin.- Nice to use against 2 or 1 high attack speed champions like Olaf, Ashe, Jax.- It is very situational item( I don't prefer it, but sometimes I have to buy it) I use it when enemy team has 3 AD high damage champions. Example: Udyr, Ashe, Olaf.- Used when you have enough of damage, and enemy team has 2 or 3 CC. Mostly used in late game, but can be used in mid game.- Used if enemy team got at least 1 stunner or something like that. Of course, you can feedl yourself more comfortable without it, altough I prefer to buy it, if I can see that enemy team has prioritet in this.- This items is used when you can't last hit as much as you would like to. Note: better, MUCH BETTER don't lose at last hits to your opponents.- This item is sooooo RARE, because there is only 1 of 100 games you have to use it... Used only if enemy team got 2 or 3 fed AP carries like Orianna, Malzahar and for example Alistar went support/ap build. It will help you to move faster and also you will have chance to heal your team more. To be honest, I don't prefer it, because it is better to get Banshee's Veil, However, Force of Nature is still viable.

Heal priority:
Yourself --> Tank --> Biggest killing spree ally --> everyone else.
Avoid teamfights if you can continue dominate your lane.

Nidalee is able to jump through walls in cougar form with "Pounce".
Here is a video guide:
Play Video

Nidalee can pull off ranked games very nicely, but you have to know her very well to do that.
Well, as I said before she can dominate her lane very well, so it's very cool if you can win your lane, especially in rankeds. She is underrated champion for ranked games. However, it doesn't mean that she is bad. There are 2 different was where to go for Nidalee. It is Middle or Top(of course solo). People really don't know the real power of Nidalee. So I wanted to say that Nidalee is very good champion for ranked games, especially at high ELO.

Pros:

Nice lane dominator.
Big amount of Heal.
Very nice damage to squeshies.
Nice mobility because of Nidalee's passive and Cougar form.
Hard to gank, because of traps.
Not high mana cost for Heal.

Cons:
Quite difficult to take out any tank.
Spear costs much mana, especially it makes sense in early game.
Armor penetration Nidalee is useless in late game.
Bad classic skin :P IMHO.

As I said before I took someinformation from Hotshot's guide. It doesn't mean that I just don't know that things and that I just stupidely Copy/Pasted it. No. I have insereted a lot of new things. I hope you liked this guide. And don't forget to comment the guide.

P.S. I will update this guide from time to time. And you can ask me different questions, I will try to answer!

And I would like to finish my guide with music :D
Play Video -HotNidaleeGG-

23.08.2011 Was made the guide.
24.08.2011 Were added Pros & Cones.