This build is for people that have some skill with shot abilities. And it consist of explanation what runes, mastery tree, items and summoner spells I use and recommend you to play with.

I bought magic penetration runes & some ability power for early game.
It gives you 15 magic penetration and 20 ability power for start at level 1.

The Mastery tree I use is 0/0/30.
Why?
Cuz Nidalee AP need lots of mana. Taking Utility Tree makes her more useful for teammates.
Also gives you more movement speed, mana regen, some spell vamp, more exp gained, more gold from the start of game (40 more + 2 every 10 sec & 40 bonus for ***sists). some cd redution and lower cd of summoner spells.

Start with dorans ring
then go as fast as you can for mejai's soulstealer.( its easy to get stacks even by assists)
If u are done with it and sorcerers boots build up Haunting Guise ( with boots and runes you have 55 magic penetration now)
After that buy Rabadon's Daethcap to get lots of ap really fast.
Next item is Lich Bane. When you have nice amount of ap why not use that and do some dmg even with basics(it also gives some movement speed ;)
The last item is for your enemies . I recommend Void Staff if enemies build some magic resists, build Eleisa's Miracle if you have problem with CC, build 2nd Rabadon if you doin good.

Q Q Q and once again Q , in fight on far distance. In middle range use W while in cat to get in melee range and spam Q/E if enemy flash out use Q in human form. ;)

Flash for survival & Clarity for mana ;)(notice build dont have any mregen items stricte.)

Playing with those all stuff goona make you laugh if you are good in shooting. Combining lots of ap with magic penetration leads to really HUGE DMG. If you do well you should have near 14-20 stacks of mejai's soulstealer and already rabadon, what gives you near 400ap =)
Then Q does like 1,5k dmg and more to really squishy targets.

Enjoy my build and forgive all shortcomings! (its my 1st and last build ,cuz Nidalee it's all what you need to win.)