Your provider will supply you with both a pre-op and post-op diet plan. You can puree just about anything though - it is the consistency that is important, so the addition of low-cal sauce / gravy will make anything pureeable (is that a word?)
You'll only be on puree for a short while, so don't go buying an expensive blender unless you wanted one anyway. A fork and a sieve do just as well.
Books mentioned on here are 'Back to Slender' (1&2) 'WLS cookbook for Dummies'.
Any low-cal cookbook is good for banders. Try your local library or search online for low-cal recipes. With a band you have to be really disciplined about what you eat as you absorb everything. Your band is just a tool to be listened to, to help you recognise you are full before you carry on with a full blowout as in the bad old days. It won't stop those sloppy calories getting digested.
If you don't think you can live like that, then a band isn't for you.
As far as preparation goes - do your research on here, look at the diaries of the successful banders - Mazza, Blue Diamond to name just 2 - and ask questions (though it helps if you do a search to see if the same question has already been answered first)
Good luck, and welcome Piglet.