It can be pretty confusing sifting through all the forms, rules, and regulations. If it seems like it will be too complicated and you would still like to prepare them yourself, there are many good tax preparation software programs that can help.
When I teach tax, though, my kids can't use the software programs. The best way to understand tax is to prepare a return by hand! :-)
Actually, that's the best way to understand the "how." The "why" is a lot tougher to understand.