I'll start by saying I am no PBC expert, there are many of them here that have helped me get up and running!
I live in song and set list mode. I mainly play at church (3 Sunday services, 1 weekly youth service). My PBC went into full time use about 7-8 months ago, and I haven't looked back. I'm running a wide array of pedals stereo. I have about 35 pre-set sounds, most are used across a wide variety of songs (clean, a couple of flavors of OD, a couple of flavors of distortion, short dotted 8th, long dotted 8th, etc...), but there are some weirder things programmed for certain songs. As we play each week, I enter the songs and their respective presets and settings into the song list. As each set is created of a given week I create a set list. Just doing this for the last 7 months, I have a library of about 300 songs. At this point I'm only adding 1-2 new songs per week.
I can do most setlist from my computer. I can mostly put together a given new song from the computer (as long as there are no crazy sounds) in which case I need to work the sounds out plugged in and save them. My board and amps live at church. So I come into practice each week with my memory stick, plug it in and load the newly created set lists (and anything else new), any play away. It's easy enough to make and save any adjustments on the fly. My biggest issue at this point is finding the song I'm looking for in the song list when creating a new set list.
I hope this helps.