Five Things You Need to Know Today: April 21

1. Clean up the Charles! The Charles River Watershed Association will hold its annual Charles River Cleanup today from 9 a.m. to noon at various parks all along the Charles. If you're interested in helping out here in Newton, and those who are interested can meet at the Hamilton Place parking lot (off Elliot Street) at 9 a.m. Following the cleanup, a picnic and speaking program will be held at the Esplanade in Boston. 

2. Fourth Congressional Caucus. The Democrats of the Fourth Congressional District to elect members from the district to attend the 2012 Democratic National Convention. The caucus will be held at and starts at 1 p.m. All registered Democrats in the Fourth District are invited to attend. 

3. Sign up for the Patch newsletter! Want to stay updated with all the news going on in Newton? Sign up for our email newsletters! You can sign up for our daily newsletter, which delivers headlines to your inbox every morning around 6 a.m. You can also sign up for breaking news alerts and receive email notifications about important stories, fires, traffic reports and more. 

4. Rabies clinic. A rabies clinic will be held today from 9 a.m. to noon at Fire Station #3 on Willow Street in Newton Centre. There is a $10 fee and all cats or dogs are welcome. For a 3-year rabies vaccine, you must bring proof of previous vaccination.

5. University Chorale of Boston College. The University Chorale of Boston College will perform Mozart's "Coronation" Mass, among other works, at Trinity Chapel () today at 8 p.m. Admission is $15 at the door, $5 with a Boston College ID.