ok so let me try to help you out as much as i can since it seems u have a mac and i dont know anything about macs lol but its pretty easy
1.first do a google search for "android sdk" and dowload the 1.5 version
2.once you download the sdk theres gonna be three files that you need under the "tools" folder they are "fastboot.exe, adb.exe, adbwinapi.dll"
3.copy these files into a new folder on your C: drive (or the equivilent of it) and name the folder "android"
this should allow you to use adb by pluggin in your phone, running command prompt and typing
cd C:\android (or the directory you put your android folder in)