I'm a recent level 50 and I've never sold anything on the market board. I've collected quite a bit of junk overtime, and at one point, I dumped a huge amount of crafting items and other stuff into an NPC just to make room in my inventory. Just the other day, I finally got a retainer and realized that I could have her hold quite a bit of stuff. I'm starting to get a feel that I could make more money on the market board itself. So before I make the leap into the great unknown, I was hoping you guys could give some general tips on how to sell.

1) How many items can I sell on the market at one time?
2) Are there any advantages to sell an item at one city over another?
3) Can I sell my items in multiple cities at once?
4) Any tips to setting a good price?
5) Any other market board related advice?