I've submitted my book (or my publisher has) for inclusion in all the usual places: Amazon, iBookstore, The Top Shelf, etc. But did I really optimize my chances for being found, by say, a parent looking for a story his 11-year-old son might actually read and enjoy?
Proofread the 'long description' of your book. Be sure to include genre, for example, children's fiction, or adventure for kids. Mention any fitting topics and keywords as well, such as skateboarding, cruiseship and so forth.