I recently got a 10" SW Dob and, after trawling here for advice, found a few useful threads. Scott's post on here
http://www.iceinspace.com.au/forum/s...ad.php?t=42081 was particularly helpful. I got a colimation tool (non-laser), a Barlow (Orion) and a Telrad.
Next planned purchase is a decent eye piece to start building up a good collection.
Good luck