It's a relatively simple process. I use the library's own online search system to reserve and suggest books. In my case, there are actually 2 different systems: the local library's own search and reservation system and Saskatchewan's interlibrary search and reservation system. I use the latter for all my searches and reservations, because it gives me direct access to everything in the province. I use the former only for recommending books for purchase.

I swing by the library once a week to drop off anything I've borrowed and pick up anything that came in.

About a quarter of the books I recommend end up getting purchased by the local library (actually a regional collection of rural libraries). Most of the rest are supplied from the provincial archives (a copy of everything removed from library shelves is retained in the provincial archives) or through interprovincial loans. If things get really desperate, there is a process for getting hooked into international lending. I remember when my dad was building his replica of a late 1920s Bugatti, he ended up with books coming from the United States and even Europe. In one case, he got a personal photocopy of some mechanical drawings that came from a private library in Italy.

My e-reading is now mostly limited to what I can get directly from publishers (Dell for the aforementioned magazines, 2600 for their magazine).

One cool thing is that my reading habits have influenced what is actually on the shelves in our small village library. They used to have no science and very little history or biography. Now they carry enough locally to justify having small sections for those. It used to be a given that I never browsed their offerings, depending 100% on interlibrary loans. Now I have to take a few minutes to see if they've added anything interesting to the shelves. The librarian says that I'm not the only one who's noticed and those categories are increasing in popularity, so it's possible that I've even shifted local reading habits a bit!