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@liloca said I can return right away with overdrive. The only thing I've gotten lately has been cookbooks though. I look through and save anything I want to try and then return the book less than 30 min after I checked it out.
I search on the library site and it will tell me the different formats it's in, regular book, ebook, large print etc, there's no special searching required. I would see if your library offers anything else or again see if you can get a card through another system that has a better ebook system/more books on it. It'd require a trip into the library for the new card but if it gives him more to read that could be worth it.
I have 7 library books in my to read pile, one I'm working on and 3 to return. I may or may not get more tomorrow

Our library system has shelves in each library with 'choice reads' that someone within the system has chosen to recommend. These books are the best because they are in the system as 'choice reads' and not their title which means you can't put a hold on the book. For all the library users that means I can renew it and for us it's twice so I can get a book for three 28 day periods which normally gives me plenty of time to read them. Then the series books I want I put on hold as soon as their in the system and don't mind waiting. Sometimes I find them on the choice reads shelf and get them before the one I have on hold, which is a bit annoying as nice as it is.
I used to spend too much on books and then moved to used bookstores but there aren't any good ones around here. My budget likes it more and I get to read way more books. It also helps that we have a good system here, the one in NC wasn't very good. But I used the used bookstore like one because you could use 100% credit. I still prefer real books though I've used my mom's ereader before.