To make the most of a library, read and read and read. Here's a sure remedy for the television habit: pile a stack of library books on the television set and next time, instead of turning on a program, reach for a book. Some people limit themselves to reading current bestsellers, but the library is full of yesterday's bestsellers which are still compelling today. Learn to use the card catalog; this is where any book can be found. Learn to use the stacks; unknown books will turn up that are exactly what is needed. Learn to know the reference librarian. Learn to use "The Reader's Guide to Periodical Literature." It is a guide to the latest information on any subject of interest. Four personal hints are: (1) take full notes when using magazines; (2) ask about the availability of reprographic machines; (3) keep a small notebook of identification numbers of frequently used books; and (4) learn how to use the reference books. The library can give help on any subject. Here are a few ideas for fun and rewarding library projects: trace family roots, find out what famous person slept nearby, cook a Polynesian feast, or take up photography. (DC)