Your mother has to file a so called I-130 form for you to her local INS office.
The form and all necessary documents plus explanation how and where to file, you can find here:
Also you can find a lot of information about your situation on that forum (just look at I-130 or family based, children to parents related questions) :
I hate to disappoint you, but waiting period is very long: now people whose petitions were approved before March of 1999 are getting their interview dates!
If you are a resident of Poland, Belarus, Latvia, Lithuania and Ukraine that use the US Embassy in Warsaw as regional (you can find this information here:
http://www.embassy.usinfo.pl/consular/iv/main.htm), it will be much faster (one to year and a half faster), if your mother fly to Warsaw and apply to the US Embassy in Warsaw directly. They have hours for an American Citizen.
If you can get a B1/B2 visa (tourist visa), as far as I know, you can wait here in US until your case will be approved.
3
I forgot!!!
Remember: you absolutely CAN'T get married because in that case your situation changed for INS and your mother has to start all over again!!!