Hi, mensaxword!
I'm not sure I can be too much help, but I'll see what I can do. Since your puzzles have been published in a local newsletter, you'd be hard pressed to get them published in a newspaper or book, since those usually buy first & future rights. That is to say, the editors might not want your used puzzles. However, you'd do best to send a letter to the editor of any publication you'd consider resubmitting a puzzle to, so that everyone is on the same page.
Now, if this newsletter is really small, you probably retain the rights to your puzzles - again, ask your editor - and could try to make your own book of crosswords. However, without a proper brandname in front or without a well known constructor or editor's name adorning the cover, the book would likely not sell as well as any of us would hope. You could contact crossword magazines like Dell and see how they feel, but in this case scenario, you may have to play by their rules.
Best of luck to you, and I hope I was of some help!
Neville