April,
"I have up to a 300mm lens, a wide angle lense, a high def lens, and a variety of filters."
IMHO, a 300mm lens is really too short for a good Moon shot. I generally use a 600mm. For whole sky shots I like the Rokinon 14mm f/2.8 IF ED UMC Lens For Canon (there are others, too). The "variety of filters" are useless.
You need a sturdy tripod. Not any such thing that is included in the so-called kits. The tripod will be in the $200+ bracket.
Remember it is always day time on the Moon so you need to use the "Sunny 16 Rule" with modification. The Looney 11 Rule does this. You will set your lens to f11, SS of 1/100 and the ISO at 100. This is the starting point as tweaks will be required.
Of course you already know everyting is in manual mode. The lens, too, is in manual focus.
For the whole sky shoots will will need much longer exposures. As you might have guessed there is another rule for determining how long you can expose. The '500 Rule'. 500 divided by the focal length of your lens. This is the longest exposure you can use to keep the stars as dots. With my 14mm it is about 35 seconds. A camera with a good high ISO is a plus.
"I would like to start taking professional style photos"
This requires professional type gear and technique but it is very rewarding and worthwhile. You will love doing it. It is "fascinating" to quote one rather famous pointed ear person. 
April,
I almost forgot to mention, you will need a good post editor. This is really where great photos are made. Not in the camera.
