Remember, I did all of my research with the assumption that I was making a 75-100 page medium-sized wedding album with black backgrounds with a $100ish budget (so I didn't even consider retailers that limit you to 50 or 75 pages, I didn't do any research on options for fancy backgrounds/embellishments, and I didn't look into the fancier pro-quality books).
1. If having a long-lasting album is important to you, make sure you go with one of the companies that prints on ARCHIVAL paper. This would include (according to my understanding) MyPublisher, AdoramaPix, Kodak Gallery, and Inkubook. Companies that do not print on archival paper (according to what I've found, I could be wrong on this) include Shutterfly, Snapfish, and Blurb. If a retailer's website doesn't advertise that they use archival paper, they probably don't.
2. Here are some really helpful comprehensive reviews that I've found. I'm not sure that I totally agree with every aspect of them, but they're a great starting point.
Digital Home Thoughts (I read this one first, and it was SO helpful!)
Top Ten Reviews (Adds in a cost vs. quality comparison)
Biggest Conglomeration of Photobook Reviews Ever (Really detailed, but judges on price/options/software, not paper/photo quality)
3. Wait for coupons. Sign up for the retailer's email list and create your photo book, and then WAIT to order it until you get a good coupon in your inbox. For Shutterfly, the best one I've seen is a free 8x8 20-page book coupon (so you just have to pay the per-page cost for pages over 20). For MyPublisher, I've been on the mailing list for two months or so, and I've already seen a Buy-One-Get-One-Free, a 30% off, and a 60% off.
4. Lay-flat pages. I wanted lay-flat pages, so I did quite a bit of research on who has them and such. Here's the summary: Picaboo has them, but only in their fanciest books, which have pretty fancy price tags. MyPublisher has them for $25/book, but they make your pages lose a centimeter or so at the gutter (center of the book). AdoramaPix has them, but they limit their books to 50 pages. A company called SmileBooks has them, but they're on the pricier side (but not too bad!) and I know absolutely nothing about their books' quality. Many other fancier, expensive-er retailers have them too, but they were out of my price range so I never really looked into them.
When all was said and done, I decided to order through Shutterfly to get the best bang for my buck (for our honeymoon and engagement albums), and I went with MyPublisher to get maximum print quality, archival paper, and great customer service without spending a fortune (for our wedding album).
I'll do a post on our finished wedding album soon... just wait until you hear how great MyPublisher's customer service was!!