If your students aren't yet sophisticated (that is, if the course is to include an intro to proofs, and truth-tables, and induction, and such) then you should definitely pick up a copy of Ralph Grimaldi's "Discrete and Combinatorial Mathematics: An Applied Introduction" ([Amazon][1], [Publisher][2]).

This book is very carefully written, and in my opinion does an excellent job of reaching students who are intelligent but who begin the course with little mathematical maturity.


  [1]: http://www.amazon.com/Discrete-Combinatorial-Mathematics-Applied-Introduction/dp/0201726343/ref=dp_ob_title_bk
  [2]: http://www.pearsonhighered.com/educator/product/Discrete-and-Combinatorial-Mathematics/9780201726343.page