Recently I gave a workshop for the Brentwood Writers Group--see the picture below of me with my harem :-)
One of the kinds of publications with which several members have had success is city or regional guides. These are booklets or short books featuring maps, photos and drawings, that cover the history and worthwhile features of a particular location. Often you can get sponsorship for this kind of publication from one or more local companies, and you can sell them at lots of locations, not just bookshops.
You won't get rich from this kind of publication--in fact, sometimes writers donate their services and the booklets are published to benefit a charity--but it will give you great experience, a bit of local fame, and good contacts for other projects.
If you live in a larger city, one good strategy is to pick out some subset of attractions, such as "Museums of..." or "The Parks of..." or "Victorian..." You can find great resources online, at local newspapers, and in the archives of schools, museums, and libraries.
Good luck--and if you decide to do one of these, let me know how you get on ([email protected]).