hi this is my first time doing a guide...and sorry for my bad english
ill try to make this a simple guide as much as possiable, and for new people to nidalee.
nidalee (in my opinion) could play well in any lane, however i prefer mid or solo top, i like them both because nidalee is a good laner, she has great sustain and poke, which is good to have both of them, i like bot because she has some supporting abilitys like her trap and her heal, and if its a 2v2 lane you'll have more chance to hit other champions with your spear because:
1- they need great focus to: get cs, dodge ur spears, and dodge/avoid your partner's harrasment.
2- because 2 champions use more space than 1, so its like hitting a bigger target.
i only dislike 2v2 lane because i think you need cs if you want to be usefull, and you wont do well with a support champion because you dont have enough damage and ADs are better at getting cs, because u'll depend on ur low-damge auto attacks to get cs pre-lvl6

pros

+ fun
+ could get easy kills with luck
+ great long ranged poke
+ great lane sustain
+ good at finishing escapers
+ good burst against low health champions
+ has a heal
+ helps at watching the map with traps
+ has a mini-flash
+ can force champions to keep distance with one spear shot

cons

- doesnt scale as well as other champoins in fair team fights( this problem could be solved in some team fights by poking with spears before starting the team fight)
- mana hungry (this problem is solved with: blue buff, or controling mana which is not hard at all with runes and some experince.. even without runes)
- even if you're fed enough one of your main abilitys is a dodge-able skill shot (spear)
- if you want to gank some1 you'll have to sacrefice ur spear damge as u want to be close to hit them with cat form (or you'll have to chose one of: cat hits, or spear high damge)

i like taking mp5 rseals because it helps my mana hunger early game.
i take magic resist glyphs only if i'm sure i'll be against an ap champion(in a solo lane), i'll take insight otherwise.
i take movement speed quintessenses because it helps me chase/escape champions, and it delays my need to buy boots.
i take insight marks because... they're the best?
* you can get magic resist if you're against early game nuker like leblanc, otherwise i'd suggest magic resist per level AND few normal magic resist

hmmmmm.... you get change the items depending on: you're level compared to others, your team, the other team's composition, your lane oponent.

* you can get trap first if you want to help your jungle (invade protection)
* you can get heal first if you screwed up somehow
* always max traps last.. i dont have to tell why, its commen sense.. if thats how u spell it

flash: its a must!!1! helps u escape,chase, etc

---

ignite: helps your cd dependency.. is that a real word?
heal: i love heal in 1v2 solo top lane.. and thats usually in low elo only

* pre-TeamFights poke as much as possible and set traps near the fighting field
* if you dont need your heal, use it on the ad carry, he'll like the attack spead bonus, you could use it on the tank if he was focused
*buy skins, they'll make you more confident thus increasing your focus, and will reward riot for thier lovly free game (lol so random :p)

*the best time to start trading with your lane oppenet at low levels is: after u use heal (because of the attack speed bonus)
-once he get in your turret's range
- if there are no low/about to be low-health enemy minions
-if there are more than 1 low health friendly minions near him (he will chose to last hit or trade back)
*use your cat form to make enemy feal safe and then jump over the enemy minions and do a spear shot (must be done fast)
*you can use your trap to be able to see in fog for a short period of time
*never start a fair team fight
*at low, avg elo tell your partner to not expect alot of damge early game and to play safe
* aim your spears with some prediction, at low elo or short range dont predict too much
* always play safe in your lane untill you have advantage
*aim your spear on squishy targets, the shorter thier attack range the better, because if they get too close again they might die
* you're great at escaping and juking, which means you can help your team even if you're obviously losing, but if you know you are losing try to keep enogh distance
* if you're 75%+ on mana and you know you wont need it alot set traps as much as you can
* flash, jump (cat form) combo is pretty cool

* if you know that they will not harras you, you better farm using cat form, if a minion is too far from you switch to human form or throw a spear if you can afford the mana
* throw a spear if you have 2 low health minions and auto-attack the other one
*you can use ur trap to push early game if you dont want ur tower to get some kills
*hmmm... dont ignite minions?

hmmm.. sorry for my lack of: colours,pics,grammer,spelling, and explainations.
BUT if ppl realy see this guide i might do major changes and make it much more offical