Redesigning Calculus I - Ideas Appreciated!

The college where I work had finals last weekend and has graduation this coming weekend.  After the festivities, I'll be officially done with work for a few months.

Although I love getting some time off, it's not all fun and games this summer for me.  In fact, I might end up doing as much (or more) work this summer as a I did last summer when I was prepping a brand new course offering.

Why you ask?  Well, I'm hoping to redo the entire Calculus I curriculum.  For the past five years, I've been teaching Calculus I using a variety of textbooks.  Unfortunately, none of them made me super happy - and based on polls I've given my students, the students didn't like them either.

Change #1:  No required textbook

I'm sure many of you have done this already, but for me (and my college), it's a big step.  This means that I'll have to write all my own exercises for the students AND update my notes to make sure all necessary information is contained within the course materials.  Luckily, my notes are fairly thorough so the second half of the problem shouldn't prove to be too difficult.

I suppose I ought to back up and state why I got rid of the textbook.  There were two main reasons.  The first, as I mentioned above, was that I couldn't find a book that pleased both the students and myself.  Some had only super easy problems, others had only hard problems.  The books that fell in the middle seemed to have muddled descriptions within the pages.  Semester after semester, no matter which book I used I would consistently get 60% or more of the students saying they never use the book (except to copy homework problems).  I already provide about half the assignments in worksheet form (homework that I've written myself) so doing the second half hopefully won't be too difficult.

The second reason I got rid of the textbook was because of the cost.  $100+ for a used calculus book is terrible.  It's even worse considering you can find most of the information online with a quick search on your smart phone (and not pay a penny - well, besides that smart phone data fee of course).

Although I've gotten rid of the textbook, I would still like to offer the students a chance for a free open source Calculus book.  Do any of you know of a good book (or multiple books) that are available for free?

This is the first post in what will probably be quite a few posts detailing the changes I'm making to the Calculus I curriculum.  As usual, I'd love to hear what you have to say!