openstax Physics is a complete algebra based physics textbook of professional (commercial) quality.
Physics Equations is a supplement that allows this book to be used in a calculus-based course.
Other online resources:
· http://farside.ph.utexas.edu/teaching.html Portions that I have read are well written and informative. Issues about copyright status.
· http://galileo.phys.virginia.edu/~mf1i/home.html Based on what I have read, the plusses are: Organized and very clear lectures. The minuses: Too much historical content for students (but profs love this stuff!). The lecture/presentations tend to have different (but effective) styles.
First year calculus-based physics:
· http://www.anselm.edu/internet/physics/cbphysics/index.html A first-year calculus based text book with a generous (CC BY-SA 2.5) license, which renders it great for doing almost anything except copying and pasting into Wikiversity (due to attribution requirements.)
o http://hyperphysics.phy-astr.gsu.edu/hbase/hframe.html Excellent reference that undergraduate physics majors will find helpful. Not a textbook.
Algebra-based (or trig-based) college physics:
· http://scipp.ucsc.edu/outreach/index2.html. (Algebra/trig based)Very short, but a great book if you give them supplementary problems and rely on lectures to fill in the gaps. Given these limitations, this book is excellent.
· http://www.physicsclassroom.com/Class/ (Conceptual, designed for high school). An excellent collection, for its level. It must be popular because search engines seem to know all about physicsclassroom.com.
Astronomy resources have been moved to Wikiversity.