How do I put my conditions for repairing a computer into writing?

I have been a fulltime student recently working on graduate work to complete a graduate degree. While continuing my studies I have maintained my computer hobby. However, recently my computer hobby has been threatening to turn into a full-fledged side business. Because I am starting to have people come to me for computer help who I have never met before (who generally heard word-of-mouth from other people whose computers I looked at) I am seriously considering putting my conditions for working on a computer into writing (for potential damage control and perhaps liability reasons). Are there any standards for this that I should reference? Should responsibility be waived for times when the computer is left in my care or any time I look at a machine? Any advice you can provide here would be appreciated. What other lessons have you learned that I should be aware of in relation to helping people while continuing my studies as a hobby? Thank you in advance.

Sample waivers for computer repair:
http://computers-house.com/repair_waiver.pdf http://www.docstoc.com/docs/27807709/COMPUTER-REPAIR-and-SERVICE-WAIVER http://javabuzzpc.com/joshengland_waiver.pdf You might want to create a limited liability company or corporation to keep your personal assets from being liable in the event some does sue over some disagreement. Check out the DIY guides here as to how to create a LLC or Corp: http://www.seravia.com/howtos/search?page=3