They have a great selection of hardwood lumber and are more than happy to let you pick through the pile. The prices tend to be very reasonable. Exotic hardwood is expensive, but Peterman's pricing is usually cheaper than the big online vendors (and you don't have to pay for shipping, which is nice). They have no problem working with small hobbyist guys like me, even though I usually just buy one or two boards at a time. The warehouse staff are busy, but courteous, and the folks in the sales office are great.
Quick tip: hardwood lumber is sold by the board foot. One board foot is 144 cubic inches. A board that's 12" x 12" x 1" thick (referred to as "four quarter" or 4/4) would be 1 board foot. At Peterman, they calculate board feet and then add 10% if the lumber you're buying has already been surfaced. If you buy rough lumber, you save that 10%, but you have to joint and plane it yourself.