most counties require pressure treated lumber for the subframe,
your deck sounds like it will be short so it should be fairly stable, running the decking at an angle allowing you to tie the ledger to the rim joist will make for a much stronger deck, this is an often overlooked item on taller decks, al those deck that sway back and forth could be avoided.
railing are required to be no more than 4 inches apart, spacing them with a 2x4 will eliminate any question as to their proper spacing, notch your posts and through bolt the ledger and or beams. for a 10 foot wide deck i would use 2x12 joists, unless you are planning a beam at about 8 foot. on a really short deck a properly mounted rim joist could be sufficient.
pm me if you have a more questions, i have built many decks for past clients. the photos are of the deck and stairs my son and i built on our house last year, 10 off the ground at the end, front walkway is 58 feet long, the addition on the end is 20x21
the depth of your concrete pier is actually dependent on altitude, 36 inches is a good rule of thumb, but there are areas depending on your location where county code is only 12 inches.
ledger must be lagged, must use flashing, use cross blocks at about 6 feet out, if you are using a beam 24 inches should be your longest overhang.