while this does not cover everything, it does give some good guiid lines.
One note on contributions .. The IRS is cracking down on this.
for cash contributions, you need a canceled check or a letter/receipt from the non profit ..
If you go to church, set yourself up with envelopes and have them send you a year end statement, telling the IRS you put $10 a week in the basket is just not good enough.
For non cash (Goodwill type donations) if you give, but don't have a receipt you can take up to $250 .. if you have a receipt, then you can take up to $500 without filling out form 8283
If you have $501 or more, you need to fill out form 8283 .. which asks specific questions about your donation ..
for valuing non cash donations, there are sites on the internet that give values for items.
this is one site