we have a belkin modem that supplies wireless internet to 3 pc notebooks currently. i bought an imac off ebay and i am now trying to figure out how to connect it to this modem so it can get internet access. but i have no idea what im doing since this is my first mac. help please and thank you!

Go to the apple icon on the top left of the screen. Select system preferences. Select network. If you are going to access the wireless click on airport, name sure it it on, then from the area that says network name use the pull down menu to select the belkin, it may prompt you for a password if you have it password protected.

If you are looking to connect it via a eathernet cable, just plug it in the back and give it 5 seconds, it will just work, no other steps necessary.