I am new to Beaverton too and was going to join one of the mom's groups. There are 2 depending on where in Beaverton you live. There are also a few meetups if you do a Portland or Beaverton mom search.
Here are mom's clubs links:
I haven't joined yet, so can't tell you if they are good or not. But I was a member of the local group when I lived in CA and it was great!