I can find some articles that explain this - but I would recommend you track down your local geek (not sure if they list in the phone book) - and ask "if they did it for you, would they mind if you watched and they explained what they were doing"?
Alternatively you can do a bit of reading beforehand - and have "the geek" sit beside you while you do it - explaining what you are doing and why, before each step. They can give you feedback in case you are about to do something wrong or "the long way".
Either way - rebuilding a PC (especially when it involves repartitioning and data backups) is always better to have someone experienced nearby - and definitely for your first attempt.
Experience also helps in knowing where applications store their data, and how to back it up, What you can ignore backing up, what can be just reinstalled. This is something you "learn" after a few rebuilds (and forgetting to capture settings or files before formatting).
Your idea of "just give it to someone who knows about all this stuff and let him do it" might get the job done - but you know your programs and data better than anyone. Finally just handing it over - when you get it back, you STILL won't know anything "about all this stuff". Of course that's not always a problem - some people don't WANT to know about "that stuff".