There is so much out there, it is sometimes hard to know where to start. I have compiled a personal Top 10 Maths Teaching Resources page. Following blogs is great as it gives you a drip feed of ideas. It may not feed directly into the next lesson you are about to teach but plants a seed for later. Again, here is my personal Top 10 Maths Blogs. And finally Twitter, which I am very much a novice at (I am @mhorley), so I refer you to Michael Fenton’s post on tips for how to get set up. Also, this post by ICTEvangelist.
With all of these things, there is the risk that you feel deluged with new information. Remember, it’s not like responding to e-mail from your boss! You don’t have to look at anything if you don’t have time. And you really don’t have to spend more than a few minutes a day looking at any of it for it to be really valuable. After a while you develop a sense of want you want to read and what you can skim over. It does take a bit of investment up front to get things like Twitter set up (maybe 30mins – 1hour), but it is really worth it, believe me!