Speaking of the AAVSO they launched a new database tool for keeping track of variable stars. It’s called the International Variable Star Index or VSX. It’s a gigantic database of a gillion variable stars from a whole bunch of sources. It allows you to enter new variable stars yourself, too. You can also search it to do stuff like this: A Catalog of Double-Mode RR Lyrae (RRd) Stars. It links out to all of the useful astronomical sources such as SIMBAD, NASA ADS and many others. If you like variable stars, check out VSX.