Not Updated For Current Season
you should have about 7-15 kills and should be doing a lot of damage if you hit a long range spear. If you do not hit long range spears or are close range make sure you use your ultimate. Your ultimate does a lot of damage mid - late game.
You will start doing a fair ammount of damage. By middle game you should have 3-5 kills and not alot of deaths. You should abuse your heal as much as possible so you do not die. You should wind up selling your Dorans ring by 20-30 mins.
Early game you will start with your Q and boots and 3 hp pots so you can farm and stay in lane longer. Nidalee does not start doing alot of damage until level 4 or until you go back to get some AP. You will have to play passive and try not to get cought.