Newsletters are still a good means of communicating with clients. E-mail newsletters, which have become all the rage, are okay but only if your clients and contacts want them. Some still prefer to have a hard copy that they can take on the train or plane to read at their convenience. Moreover, many people do not want to receive e-mail newsletters because they receive too many e-mails, period. I had one firm tell me they like the touchy, feely of a hard copy. Of course, you should give your clients and contacts what they want.
I ran across an article from Morningstar Multimedia which gave some basics on newsletters, and it may be worth a look. What ever format is best for your situation, newsletters are still a good idea.