There's a program called Punch! Home and Landscape to help with the design, estimates, and stuff. It's not exactly a barrel of monkeys to learn how to use (of course, typical construction guy, I chose to learn it by mucking about with it as opposed to, you know, something clever like reading the online manual, so your mileage may vary). Once that was done, though, this sucker is very elegant, makes great 11x17 prints and estimates quantities, which I can then take to Menards (midwestern home improvement chain) so that I can start crossing stuff off after seeing prices and ciphering costs. Regardless of crushed dreams and never-installed jacuzzis, its a great little program.
*actually, have to narrow that a bit. I can build, but show me a car and I start looking for someone to give money to. Blinker fluid at $19 a pint? Maybe I should buy a second pint then, keep it in the garage, for winter driving emergencies.