Books are heavy!  I usually take a tote bag with several doubled plastic grocery sacks on our library ventures. The sacks allow easier toting of books. Even the 4 and 6 year olds can carry quite a few with this method. A friend of mine favors a double stroller (laid down for maximum hauling capacity), while another family pushes collapsible, wheeled carts among the stacks.

Once the books arrive home, have a special spot reserved for borrowed resources. It can be a plastic crate, a designated book case, a cupboard, an end table, or a generous-sized basket or two near the hearth. Having all family members educated in returning books directly to the designated location prevents scrambling to search under beds and behind dressers.

Something in me cringes at the notion of paying late fees. They fall in a category my father referred to as a "stupidity tax." Make sure to note the date that your materials are due back.  Some homeschool planning software will notify of due dates entered in, and many libraries with online services send email reminders a few dates before books are due. If, like me, you are fortunate to have your library keep your account online, checking due dates, and even renewing books is easily done in a few keystrokes. Whether your library has online service or not, simply writing, "Library!" on a calendar works too and is a good backup!

Ensure also that all your materials get packed into the van on library day! Before our library kept accounts online, I would keep the printout of titles borrowed by the calendar, and go through the list checking off books as I loaded sacks to return. Now I ensure we have them all while looking at the online list before heading out the door.

One other handy tip: Some libraries have special privileges for school teachers, and extend them to homeschoolers as well. A friend of mine obtained a teacher card from her library which allows her to check out books for two months instead of two weeks! Last I knew my library didn't offer this option, but I think I'll inquire again.