1. Go to setup in blackberry
2. Setup Wizard
3. Email Setup
4. Then just follow the instructions on entering your e-mail address and password.
Or try downloading the gmail app from blackberry app world. You should be able to set it up that way too.
The e-mail setup will reconize it as a gmail account and add the gmail icon to your blackberry. That is how my blackberry bold 9000 does.