The National Association for College Admission Counseling (NACAC) has a great booklet for families starting the college admission process, called Guide to the College Admission Process, and some great resources available at their web site. If your school does not provide a lot of college counseling, this website will be a great guide.
There is an overview of the college admission process, a list of things to do in the junior year, great advice about visiting colleges, starting an admission folder, keeping track of what you learn about each college or university explored, whether it is online or in person, and some great advice for the senior year, and parents, as well!
My favorite part was Appendix C - a month by month calendar for the entire college process! Have fun!