the 7700 series has these: USB Cable with Charging Capability RIM BlackBerry 7750 7730 7780 Cellular Phones
USB (computer) on one end and a MINI-USB on the other end (goes into phone).
They may have given you the wrong cable, however, it's not a big deal. The mini-usb cables are like $9 at your local computer retail store.
From there, goto the Blackberry website, and download the software if it didn't come with it.
Goto: BlackBerry - BlackBerry Support | Knowledge Base, Product Documentation Software & Support Programs
and choose the "Download BlackBerry device software »" link, and follow the instructions.
Once you install it, it should be easy