You can use Brewbuilder on the brewmasters warehouse website to add extract, grains, and develop the hop schedule. It will give you a good idea of the IBUs, ABV% ans SRM. Sorry i dont have anything creative to add other than that, but i have been using Brewbuilder lately and I find it very useful!
It can be fun to just throw caution to the wind and make a random brew, but its a lot of work to brew and i hate not having some sort of style or taste in mind when i start a batch.
Either way, good luck!