Here are some of the top companies and resources in the scanning field.
Manufacturers of Home Scanners
Canon is a very respected maker of a variety scanners. Their specialties are flatbed photo scanners and all-in-one printer scanners. Canon has how-tos and instructional videos on their site for the new user. They even have a crafting corner page with information on things like scrapbooking with scanners. If you need to find a manual or update a driver, just search by your model number on the service page.
Epson is also a top name amongst scanner producers. Their specialties are also photo scanners as well as document scanners. Information on drivers or general support for Epson scanners can be found here. Epson also has a special page for Apple users to help you find the best scanners for mac.
Fujitsu is a well-respected maker of document scanners. Their document scanners are some of the fastest and most versatile. You can find data sheets, drivers and support videos for Fujitsu scanners on this page.
Brother is a lesser name in scanners but are well-known for their multifunctional printers. They also produce portable document scanners. If you are shopping for a portable unit the have a nice comparison page available.
Mustek is primarily known for their affordable large format scanners.
Wolverine is the leader in digital image converters for slides and film.
The Neat Company
The Neat Company is the leader on receipt scanning models.
Tips and Instructions for New Users
This website has general tips on scanning photos. Particularly helpful for understanding resolution and how to choose what dpi to scan at.
University of Missouri Printing Services
Contains some general scanning tutorials.
Very basic scanner tutorials including how to set up a scanner. Use the search function to find more advanced tutorials like “how to scan in Windows 8” or “how to scan to photoshop”.