To check and recharge a ac you need a low and high side gauge kit.
http://www.ackits.com/merchant.mvc?S...erantGaugeSets
http://www.ackits.com/merchant.mvc?S...egory_Code=DIY
If it is auto matic ac controls a good body/HAVC capable scanner will check thing out and read any codes.
If you do not have the proper tools to do it it would be best to find a good repair shop and have them check it out.
Good Luck
MT