Backyard Moon Shot
The NASA Site APOD, or Astronomy Picture of the Day is an awesome site that has an amazing Astronomy picture every day and is curated by Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
This great site by Josh Worth, in his words is a Tediously Accurate Scale Model of the Solar System.
Free charts for whats up on the sky for each month.
A great free resource with interactive star charts, ISS and satellite passes for your location, currently visible comets, current location of the Tesla roadster and Starman. If you are looking for something interesting to observe, the tools are here.
The Milky Way project is a citizen science project. Want to do real science classifying data? There are a host of projects you can participate in at the Zooniverse, may favorite is the Milky Way Project!