I know if you are on a Mac, you can use Aperture to organize and batch your photos and have Apple professionally print a photo book designs in Aperture for you. Some pros use their own printers. Epsons are really good, but the good ones you have to drop some change for.

I’m thinking a professional photographer would likely have their own darkroom.

[edit: I’m tired. Minus points to me for failing to read the entire question(s)]

Walgreens.

Walgreens, CVS, Rite Aid, etc. Even Staples or Wal-Mart for that matter.

Put your photos on a thumb drive, bring it to said store and processing usually lasts an hour or two. Professional quality prints. The only folks who have darkrooms are those with non-digital cameras, btw.

@NGYoshi: Kodak actually partner with Apple to do the print. They are professional quality photos, as with many other online delivery printers.

It depends on what you mean as for as “printed” If you mean photos ranging in size from 16×20 inches to ones I have print 60×70 inches, then you need a place like Adorama, if you mean photos printed on unique paper types, then you can do that from you home. I own two Canon 9500 and one Epson 1800 I do all my printing on. They let me print on pretty much any medium that will fit into the printer. The max size is 13×19 for those two printers. If you are looking for a professional post-processor, then you are going to have to put out an ad for one, as most are work from home nuts.

http://mpix.com is good. CostCo surprisingly has all of their printers profiled, so they’re good too. A good photobook site is http://pikto.com as well.

I use http://smugmug.com

My Mom uploads her images from Picassa through CVS and then just goes to pick them up. They are great quality.

http://Fullsizeposters.com if you’re NOT in a hurry.

Otherwise, what pros do is if they have to have stuff printed in a day or so they go to their local camera/printing store and pay the hefty price to do it there.

Fullsizeposters is the best, excellent prices, literally ANY size you want, customer care can’t be any better and is pretty much near instant, I don’t suggest calling, but by email if someone is at the place they’ll respond real quick.

I have had good experience with MPix as well.