I use photoshop,currently PS6 but I started with PS3 and in some ways I think it was better than 6 version.
Then again I was younger,everything is easier when you are younger
Inscape was mentioned a lot in other posts.I never got a hang of it,possibly because I'm so use to PS.If you didn't use PS before Inscape might be better option.
I think Bruno (S&P models) is using MS Word for making of his models.If you have one try it,it might work for you.