separating tracks and mixing skills

Sorry, the tracks dont bleed into each other. Rather they seem to mash together.As I said, they lack separation.

One easy way to get a more "disciplined" frequency structure in the mix is something like:

Put a Hi-pass filter on the guitar tracks somewhere around 150-180 Hz and pan them a little apart.

Depending on the type of sounds you're using put a different HPF on bass and kick drum at around 40-55 dB, allowing one of them go lower than the other. If the kick has a boomy reverb,  change it. Putting a little boost on the kick somewhere in the upper register of the sound (200-600 Hz) helps it to cut through.

Remember, that if all the individual instrument sounds sound "great" or "awsome" alone, they most likely are unusable together.

Your drums are not disappearing anywhere, obviously. It's just a simple fact that all instruments can't be up front.
If the riff guitar has  growling lows starting the song, you have to EQ those lows out when bass jumps in, otherwise you get a mushy porridge of lows etc. Even the left hand parts of a piano or an organ can sometimes fully sabotage the bass guitar, and need to be cut severely.

This can also be very much a monitoring question. The more experience you gain and the better monitoring circumstances you get, the better decisions you can make. What I wrote here is only a simplified  "first aid kit".

Roey Izhakis book "Mixing Audio" was a very useful book for me. It also includes a CD with sound examples. There are other recommendable ones, too, I'm sure.

A high-pass filter allows higher frequencies to pass through, while dimishing lower frequencies. In Kalle's example, frequencies below 180 Hz would be rolled of to give your a brighter, less muddy sound.
I believe SHS7 came with the Sonitus EQ. Check your list of effects to be sure.
If so, high-pass is one the preset options within the Sonitus EQ. Or any EQ for that matter.
If you are recording your guitar tracks mono, as you should be, they will initially pile up in the middle. That's ok. Mono tracks are very easy to pan, as Greg suggested.
Spreading your instruments across the stereo field is a big factor in getting separation.
EQ helps by giving the instruments definition.
Reverb defines the space around the instruments.
If you can get a grasp on these three basic elements, you are well on your way.
By way of example, give this a listen(preferably with headphones):


http://soundclick.com/share.cfm?id=11243952
Do you hear how each instrument has its own sonic space?
The guitar tracks were recorded mono, right up the middle. But by moving them around, and giving each a slightly different EQ, they become separate, full bodied entities.
Does that make sense?
Above all, don't get frustrated. It takes a while to learn this stuff, and we are still learning.

Solo each track. You should only hear the instrument recorded on that track. If you're hearing instruments from other tracks, then you are routing the playback back to your soundcard when you are recording tracks. If that's the case, you have a routing issue and you have to figure out how the playback is getting re-recorded. It could be a setting that needs to be changed in your soundcard's control panel or if you're using a mixer, you're mixing the playback with the record input.