You can also use direct email to your contacts. I usually just send a link to our blog to our contacts with a short message so if they are interested they can go to the blog, or if not, they can just delete the email. You should send the email to "An Undisclosedlist of Your Town Sister City Members" firstname.lastname@example.org with the actual addresses to a bcc address - that way spammers won't pick up the addresses and harass your email contacts.
It is your choice whether you use a simple email format or one with an attractive photo or letterhead - the attractive letter head looks nice but takes longer to open and will not work on everyone's computer.
Social marketing is evolving rapidly, but you can get underway quickly with no cost and a little effort. It takes a reasonably computer savvy person a couple of hours to get all this up and running, and then some time to develop a little skill.
The buttons at the bottom of each blog post make it easy for people to send your blog address to their friends on Facebook, Google+ or Twitter. You need to be logged into all of your systems for these to work.
You can create lots of different blogs with different looks. A couple of examples below: