Did you use any online services? Or hire a local lawyer? Care to share approximate cost?

No I filed it myself. It was 5 years ago now but I remember the process being fairly simple.

I see you're using PayPal to take donations - any problems with that or considerations of alternatives?

No problems yet. It's quite annoying that PayPal takes a fee from each donation. That part doesn't sit well with me but I haven't found any alternative that takes a smaller fee.

Also very curious to know these questions, and the ongoing cost/maintenance/bookkeeping to maintain 501c3.

As far as the cost, there was an upfront cost that I paid out of pocket (not from donations). Each year I have to file a IRS form 990 and a annual report which are both very simple at the moment because my bookkeeping is quite simple as well. Bookkeeping is like any business. You need to track where each penny goes. That hasn't been an issue for me due to the small size of the charity.

I hope that helps.