July is an Excellent month to submit to agencies. (Pilot season has lulled and there's a short break between episodics. A lot of agents have gotten rid of clients who weren't booking so they have a few openings now.) Get your half page cover letters highlighting recent jobs, your updated resume, and your headshot that looks like you all in a manila envelope and start submitting!
You can go to Sam French and pick up "The Agencies" book which has almost all the agencies listed as well as which agencies are looking for who (ethnic actors, biligual, kids, hip and trendy, etc) and submit away!
But wait! Don't forget your stamps! All the above weighs in at just over an ounce so the United States Postal Service will return all your submissions unless you slap $1.05 in postage on them. Yes, being an actor is costly, but why not get all your shizz done and then start off your July with a bang?
In the mean time, Happy Independence Day! Wave a flag and sparkler for me!