Linda, A lot depends on the size of your guild and the levels of experience of the members. If it is a large guild with funds available for speakers etc. there are lots of "professional" quilters out there who will come to your meetings for a fee. They are usually pattern designers or have come up with some new technique that they are willing to demo if they can then sell their merchandise to your members. Here in the Mid Atlantic corrider there are a lot of them. Mimi Dietrich is the founding mother of one of the two guilds I belong to. She is a marvelous speaker and has designed many quilt patterns and has published several books. She is also a two time breast cancer survivor and a real sweetheart.
If most of your members are beginners you might have more experienced members take turns doing demos of basic quilting skills like paper-piecing, rotary cutting and the proper way to press rather than iron etc. Handquilting techiniques and machine quilting techinques always come in handy. Even how to layout a design and making the quilt sandwhich are skills that many quilters have not yet mastered. There are kinds of basting techniques. Making and applying binding is always a handy skill to learn.
Block of the month is a way for a group to acquire quilts for a show etc. Someone agrees to pick out blocks, usually simple, basicand of a certain size to begin with. Each person is given written directions to make the choosen block. Instructions like color choice, solid or prints, plaids, floral etc. can be part of the deal. Sometimes the instructions just say that one certain color or pattern must appear somewhere in the block. Each person who takes the instructions should make at least one block. The blocks are returned to the guild at the next meeting and each person who made a block puts their name in the pot. Whoever has their name drawn wins all of the blocks. BOM gives members a chance to try a block without commiting to a whole quilt. Those who win the blocks are urged to complete a project with them.