I vote for once a week, too! I wouldn't really care if it's colorful and cutesy...I'd just want to know what's going on. I don't think you need to send a bi-monthly newsletter if you are sending something home weekly. I found that when I taught 1st grade the kiddos were excited to share with their parents what was going on, so that combined with my weekly newsletter was enough to keep them happy. Now that I'm in 5th, I have the opposite..."they tell me they didn't do anything in school this week"!
