Hey DKB,
I was going to bring up all the point that everyone said already. Some of the Big problem ones Is the F8 you would need to have Full sun to get at good image or have your ISA pushed up high. I looked in to these lens at one time many Moons ago (hehe)

They sell them under about 5 different names (Opteka and Phoenix is two of them) which for the price is very tempting ($65-$250)They also have a few zooms round 420mm-800mm. and a 650mm-1300mm then with a 2x you get 840mm-1600mm and 1300mm-2600mm Now don't forget the F-stop is Now F16-F32 Not good. With lens the more you zoom up the more shake will be seen. If the tripod that came with it is not strong you can use two tripods one for the lens and one for the camera. You need a lot of light and very low movement. Try the lens on a stop sign (stop sign don't move much)

in the Hottest day of the year,

you should get a good image. Note that most of these ads show an image of a sign in summer. Now don't get me wrong you can get people, birds etc... but you need light, a lot of light to work the best.
As for astronomy gos Many people think low light needs slow shutter speeds this can be true but not true. If you let your camera think you are taking a picture of the moon for an example it sees the bright moon and the dark space and thinks it needs slow shutter speed. Not true, you need to meter off the moon itself, you know it bright right. If you just let the camera do what it thinks it needs to do, you will get a very bright spot (blown out image of the moon) Also, even though you may feel that your tripod is not moving the Earth is and so is your tripod, yourself, the cup of coffee in your hand etc... Unless you have a tripod that has tracking (moves at the speed the Earth is moving) any slow shutter speed will blur the image. Kind of like a slow shutter speed in a moving car out the side window (the camera is not moving the car is but the camera is in the car). Get it?
If I ever get the time maybe I should write an article on Astronomy photography, it comes up a lot. Maybe some day.
I know I have posted this image before but here is an example of what can be done. I can't remember what all the info for the image was but It was maybe done at a 90th to 125th of a sec with a 1250mm lens at F4 (telescope) the end where the image comes in is 10 inches across (254mm across) It also has a tripod that tracks (moves with the Earth) So for dimmer subjects like Nebula's, other Galaxy's that need the slower shutter speed the tracking keeps the camera moving right on track as the Earth moves under the subject (or if you want to think of it as it moves with the subject across the sky)
As for basic camera terms:
I don't know how basic you want to know. Do you understand F-stop, Shutter speed, ISA and how they work together? let me know where to start in the basic and I will try to help.