JonJon,
Welcome to the wonderful world of home recording. You've come to the right place.
I think that almost everyone here at one point had similar sentiments. And certianly those new to the game expecting to make a professionally sounding CD is quickly frustrated at how difficult it is. But as you probably know, recording is an art form in itself, or rather can be classified as "engineering" and it takes a lot of practice to learn how to do it right. Getting a good sounding recording is much like learning to play a new instrument, and it will take alot of time and experimentation.
Since you have
a VS840, you've got 8 tracks of digital recording at your disposal, plus all the basic Roland effects you'll need. Right off the bat you're off to a good start. But what you need next is a decent mic (prefereably a condensor) and a decent preamp. You don't need to shell out major bucks for either of these, but with those 3 elements you can make a recording close to what you'd hear on a professional CD.....with time and experience.
The "art" of making a recording comes from the following elements, each a discussion topic in and of itself. YOu can search these posts for advice and instruction on each of these, but in a nutshell, to make a good recxording you'd have to have:
1) A decent performance to start with
2) Select the right microphone for the job (i.e, a condensor on vox, acoustic instruments, dynamic on amp cabs)
3) Select the right mic placement for the instrument you are using
4) The right combination and setting of the input (i.e, not too hot, not too soft)
5) The right application and settings of FX on input (i.e, compression?)
6) Once these are done and your tracks are recorded, you must learn how to mix. What/how much EQ and other FX do you apply to each track?
7) Mastering is the final step, and generally where much of the *sparkle* comes from. Mastering adds other FX to enliven the sound, but if you're making a demo CD it might be worth your efforts to learn how to multitrack properly, then give your premaster to a professional to master for you.
Work through each step laid out as above, mastering each in time. For example, if you have a piece you can play well, ask advice here on how to mic it and which mics to use. Once you have that down, you can play and tweak your FX until you get a sound that is clean and one you like.
It takes time, no doubt, but there is a lot if information here that will help you on your way.
PS: If you haven't already, get a copy of the VSPLANET Comp CD to hear what other people can accomplish using the same machines as yours.
Good luck