No form of normal leveling can take place after level 30, unless you have dead money for the XBOX only I think.
Or are on PC / laptop and mod the game.
You still can raise skill points, however by using skill books, that raise 3 points per book, or 4 with comprehension.
If you want to try and max out your skills you could save them up and use them at level 30, but I don't see the point tbh.
Perks you can only gain the 15 you get from leveling on the level up list.
However if you keep using different guns, items and other things you can gain extra perks for free.
Heres a list of all perks http://fallout.wikia.com/wiki/Fallout:_New_Vegas_perks