Jerry,
As a board member of a mid-size library with relatively strong local funding support, I know that there is never "enough" money. Currently we are facing some major structural problems that are going to cost a few hundred thousand to adequately address. This in a tight economy. Sigh ...
There are many simple ways for individuals to support libraries, and checking books and other materials out is the first step. If you live in PA, you can contact your local legislators and urge them to "unfreeze the funding formula" (ask your Librarian to explain what this means). This is an especially important step to help small libraries. You can request books via Interlibrary Loan. That helps. You can walk into the building, early and often. Each visit counts. Ask questions at the Reference Desk. Log onto the website. Attend programs at the library (if they have them). Offer to present a program or teach a class (maybe on writing). Start a writing group at your library.
Aside from that, put in requests for the books you want. Most libraries are happy for patron input, because that helps them stay in touch with the pulse of the community.
Every now and then I check out a book that really rings my bells, and I'll buy a copy to keep on my shelf after reading the one at the library. But more often, a couple of years after I buy a book, I donate it to the Friends of the Library Used Book Sale, and I buy many books there. Another way to support the Library. If your library doesn't have an FOL Used Book Sale, volunteer to help start one. That is a huge PR boost for the library and lots of fun to work on.
Many people think libraries are on the verge of extinction. Not true! But they are morphing into community centers, electronic research tools, and multi-media resources as well as purveyors of traditional print media. They are more important than ever.