Linear Algebra is a text for a first undergraduate course. It is Free. Use it as a main text, as a supplement, or for independent study.
Get a printed book
You can get a paper copy for just about the cost of media, about $28. Click on the Amazon link below or you can use ISBN-13: 979-8362590277 at your favorite site. Bookstores can buy from NACSCORP or from Ingram via LightningSource.
Some people who are not me also sell the text. They charge less. Note that if you buy it from Amazon for less than $25 then they will charge you shipping and it will end up costing you more than the $28 I charge.
If you are thinking teaching out of this text then note that you can register with OpenIntro.org to receive a free paper desk copy (this organization works to make texts like this one easier to adopt).
Are you teaching with this?
You may find useful a number of ancillary materials, including beamer projector slides and a lab manual using Sage.