I'd like to add a couple of extras: 7) Errata documents can be very important, at least give them a quick glance before deciding on a part. 8) If you are prod

I'd like to add a couple of extras: 7) Errata documents can be very important, at least give them a quick glance before deciding on a part. 8) If you are producing any significant quantity of a board, do not use the Digi-Key or Mouser parametric search. Find manufacturers through these and other sources, then look for parts on the manufacturer website. 9) Do not use NRND (not recommended for new designs) parts if you can avoid them. These parts will cause you pain. 10) Read the datasheets for odd packages carefully. The "flags" (pads) underneath TSSOP chips can be connected to VCC, VDD, or GND. 11) There are packages even more painful than BGA (such as LGA).