I've just updated myself
My recommendation is to backup any files you need eg personal docs and do a clean install of F8. Upgrading is notoriously tricky, and usually only done 1 version at a time eg F6 ->7 ->8.
F9 has only just come out, so I'd let it stabilize first.
Also, go with 32 bit install. A lot of SW is still only avail as that, and you won't really benefit from 64 bit unless you use massive DBs for example.