better yet, learn for free by searching this forum and look at http://www.parktool.com/blog/repair-help

i've got an sr400 recently myself and have been riding the snot out of it. I absolutely love it. My suggestion is service the bare minimum to get it roadworthy and then ride it for a while before upgrading. You'll get a better understanding of what and how you'd like to upgrade this way and likely save yourself money and end up with a better fitting and performing bike.