I am new to paleo and am not sure what I can eat. I cut out carbs from my diet, but I eat plenty of fresh veggies, I want to know if sweet potatoes and corn on the cob are alright to eat and are there any fresh veggies and fruits I should stay away from?
Short beginner's answer: anything that isn't processed 'cept grains and legumes. Strive for the highest quality protein sources: grass-fed/pastured beef, wild caught seafood, uncured meats (like uncured bacon or sausage).
Longer answer ...
You DO NOT have to cut out carbohydates from your diet to get started on the paleo lifestyle. Paleo types do not eat grains (and their products like bread), and some other carbohydate dense foods, but we do eat plenty of vegetables, fruits, and nuts that contain plenty of carbohydrates.
Some paleo types do opt for a low, or very low, carbohydrate diet (LC, VLC). This is NOT required to join in on the paleo fun. You will find that eating paleo may not be VLC for you, but you will almost certainly be consuming less carbohydrates from crap sources like you would on the SAD (standard American diet).
Sweet potatoes are AOK in general (definitely great if you are active). Corn is straight out -- corn is a grain, not a vegetable. Don't overdo it on the fruits -- lots of sugar and possible issues with fructose make them only a healthy, sometimes-food, but maybe not one to indulge in every meal.
I suggest reading Robb Wolf's "The Paleo Solution" or Mark Sisson's "The Primal Blueprint" -- they offer a quite level-headed approach to getting started on paleo, and enough background to understand why these changes are important for your health.
There are lots of ways to fine-tune your paleo-eating, but in general most plants and veggies are AOK.
There are a couple of tricks to figure out what's safe on Paleo:
1) Google it. 2) Search for it on PaleoHacks. 3) Eat it and see how you react to it after not eating it for awhile.
Here's also a flowchart and while it's not perfect, it's definitely a good basis.
Although it's not technically "paleo" I think a very helpful place to start is Kurt Harris' archevore because it treats things in order of importance. Line your ducks up, so to speak.