I asked the same question a few days ago on the chat rooms, and there seems to be some consensus over the following texts:
Linear Algebra 4th edition - Friedberg: This book is particularly focused on theory, with little to no examples that are taken from other fields (such as computer science). However, if you fully understand it, you should be able to apply any of the concepts yourself. It is a pretty challenging text, maybe one of the richest ones. So this should be a good bet.
Hoffman/Kunze Linear Algebra
Axler's Linear Algebra
Strang's Linear Algebra Applications and Introduction - This is a good book for applications to engineering, etc. It is the book they use for the MIT OCW course.
These should be good books to get you started right away. However, also make sure to check out online resources and videos, such as MIT's OCW material on L.A, and other easier reference guides such as Paul's notes. There are plenty of online pages that were put up by courses at many different colleges, so you are bound to certainly find tons of materials, such as notes, homework problems, exams, etc.
EDIT (links): Berkeley, MIT (theoretical)
Hope this helps.