I started using 1dollarscan.com. They have a "platinum" program that for $100/month[1] you can scan 100 "sets" (each set is 100 pages, so a total of 10,000 pages) with the basic enrichments (OCR, tuning to particular devices). On some volumes I ponied up for the color and/or 600dpi options.
Did that for about 6 months and processed a bit more than 60,000 pages. I bought a nice guillotine cutter off Amazon and a ScanSnap 1500 scanner [3]. For a lot of paperback references I could cut the spine off, drop it into the scanner, and it takes less than minute to scan the entire book, both sides of the page. I also scanned a several years of Scientific American, Nature: Materials, and other magazines I've kept for reference. Yes it "destroys" the book, generally though I'm ok with that. If I really want something in book form I'll buy two copies, scan one and keep the other. For reference material it is much more helpful to have things digitized. I've been working on a home grown data management application which catalogs and cross references information from the books. The whole library is less than a terabyte at the moment.
[1] 1dollarscan platinum membership -- http://1dollarscan.com/membership.php
[2] Stack S12 guillotine cutter -- http://www.amazon.com/dp/B000YI5P76/
[3] ScanSnap 1500 scanner (current model iX500) -- http://www.fujitsu.com/us/products/computing/peripheral/scan...