Things you need:
1. Firewire port/PCI card. Some cards are flaky with the 722 and vice versa. Seek recommendations or prepare for the trial and error at this point. This is not exclusively a 722 problem either; some firewire cards just suck. Get a good firewire cable, too. Like cards, some cables just suck. Note: at the moment, the 722 does NOT like being daisy-chained. It needs to be the first and only device off a Firewire port.
2. Once the 722 is connected, it appears as a drive on your computer. Drag and drop or copy and paste files from the 722 to a local drive. Do not do your editing on the 722 itself.
3. I use CD Wave to split tracks, then Wavelab to join tracks that were auto-split by the 722. After that, I FLAC and burn the FLACs to a DVD with Nero. On a Mac, I'd use Spark to do the first two tasks and then Toast (?) for the DVD burnging portion.
4. HD space = about 2 GB per hour of stereo at 24/96. Multiply or divide for different sample rates. Double that if you're doing any editing (anything other than splitting tracks). Plus you should always have a GB or so free on your primary drive anyway.
5. Keep an eye on the SD support forum for updates.