Vote Smart
Here you can look up your senators and congressional representatives and find out about their voting record, their funding, what they've said, and so on.
USPS Online Store
For those of us who hate to stop at the Post Office, use the link above to go online and order stamps. And if you don't keep envelopes on hand, you can also order stamped envelopes.
We've heard that, due to security measures, postcards reach their destination in the House or Senate quicker than letters in envelopes. Postcard stamps are only 34 cents, and you can buy blank postcards singly or in bulk from a variety of places - for example 50 cards for $8.95 from Amazon.
US Politicians on the Muslim Ban
This google doc created by Jenn B. Caballero shares the responses of Senators, Representatives, Governors, and Attorney Generals to Trump's executive order banning people from 7 majority Muslim countries. There are also sample scripts to use when contacting your government officials if you're uncomfortable on the phone.
Fax Zero
Preloaded with congressional office numbers, this service allows to to fax letters to your representatives easily and for free.
The Indivisible Guide
A practical guide for resisting the Trump agenda written by former congressional staffers revealing best practices for making Congress listen.
Google Alerts
Sign up for Google Alerts. Sign up to find out what your Senators and Congressperson are up to - hear when they're about to make a public appearance, when they make a statement, when they're in the district, when they're in DC, etc.
MoveOn.Org
This is a great place to find out if there are any upcoming rallies or events near you and to read news about the #Resist movement.
Russia-Trump: Who's Who in the Drama to End All Dramas?
Confused by the dizzying cast of characters and the many twists and turns in the Trump/Russia/Mueller saga? Read this helpful synopsis by the BBC.
President Trump's Lies
Having a hard time keeping track of how many lies Trump has told since he assumed office? That's because, according to this handy piece by the Washington Post fact checker blog, the number has topped 3,000, with his daily rate increasing the longer he holds office. There is a list of some of his biggest whoppers, although to be fair it's sometimes hard to say whether he speaks out of mendacity or sheer encyclopedic ignorance.
White House Revolving Door
The White House administration turnover is higher than in the last five presidencies, as detailed in this CNN overview of departures.