Here is some unsolicited advice since I want this thread to be successful for you:
Get this thread in order, complete with books still available and asking prices, in a clear, organized fashion. Post everything in your collection you are willing to sell off. When someone buys something, reply to their PMs and assure them that you are sending their books. I suspect that you will complete way more sales if you took these steps.
Along with the above, invite others to donate money by bumping your PayPal address once per page. Do not spam people who donate with PMs asking for more.
Lastly, invite others to donate their own books directly to this thread whereby they handle the transactions with buyers separately but have payment sent to your PayPal.
These boards have generated some very fruitful charity threads over the years using the above methodology.