Depending on what you want to do.. a sampler, a design from a photograph, a design of your own, etc. there are a variety of different methods. This isn't a very easy question to answer. :-)
There are several computer programs out there to help - PC Stitch, Stitch-A-Photo, Pattern Maker Software, Pattern Maker Cross Stitch Clipart, and I'm sure there are more. These software programs will help and provide you small images that can be used in your designs.
If you are trying to do a sampler of sorts you could just start with a book of drawn thread and cross stitch stitches and design your own on a piece of graph paper.
I would think the 'simplified' version is to find a software program that provides you with some of the functionality you are looking for.