OK, so I've got an iMac, I guess it would be a late 2009 edition. Intel Core 2 Duo 3.33 GHz, 8 GB RAM, ATI HD 4670. It's running great, it has Snow Leopard on it. Other than the builtin software, I mainly use MS Office, Dreamweaver CS4, and Fetch. I'm looking to upgrade now to Lion just so I can keep up, and mostly so I can install the iMessage beta (which yeah I guess I'll eventually upgrade to Mountain Kitty update I don't really care about upgrading but I'm feeling left behind now with the announcement of mountain cat/lion/whatever. Anyway, I've never done an upgrade on a Mac before. Do I need to do anything special before I do the upgrade? I've already got a Time Capsule and it's been backing up well for months now so I don't need to back anything up. Any tips or tricks for me for the upgrade process? I read I should probably make a DVD/USB copy of Lion after I download, before I actually upgrade. Thx.