I just recently did a down a dirty recording for a guy. 3 hours to record, mix and print a CD of a song. It had drums, bass, one guitar, and one vocal. The song was a Valentine's Day gift for his wife.
Anyway. Obviously no time to really "check" anything while tracking. In these cases, you go with you gut and make VERY course adjustments in mic placement and/or instrument sounds. So, most of this stuff was "throw the mic in front of it and make sure it isn't horrible" type of production work.
So we track it and then I have 15 minutes to make a mix of it.

We were mixing in a Yamaha O2R digital mixer (it is WELL documented on here how much I detest the sound of this console!!!). So anyway, it just seemed like no matter what I did to the tracks, whatever I did do made it sound worse. Yes, a little low shelf roll off on the guitar a vocals worked out okay. But nothing in the forms of compression, reverb, etc. seemed to add anything "cool" to the sound.
Was it tracked to well like possible pipelineaudio suggests? Hell no!!! It was tracked "ok" at best!
Don't ignore how well your tools work! There are eq's that just don't sound good. Mackie comes to mind!

The Yamaha O2R's eq's are horrible. Same with certain compressors, reverbs, delays, etc...... In this case, the O2R just didn't have the "right stuff" to do quick work. I could have done a much more effective job in the same amount of time using damn plugin's! But no time to transfer the tracks into the computer for mixing in this case, so I HAD to use the O2R. But it did amaze me just how horrible it's on board DSP really was. Even slight amounts of compression on the vocal sounded horrible!
The thing was, I just completed a big project for another band. Mixed entirely in Sonar with mostly Wave's NNP plugin's. I was just too used to better tools. These tools do a better job set wrong than anything the O2R could do at it's best!
So, don't forget your tools. If you have just crappy ol' stock plugin's to work with, you would probably be better off doing as little DSP as possible. I have yet to hear a software reverb that approaches mid level hardware reverbs on 99% of things it could be used for. The stock compressor in Sonar is pretty much unusable. It's eq's are harsh. So, I avoid those plugin's at all costs! The Waves stuff may be more taxing on the system, that is precisely why they sound so much better.
Even on analog mixing consoles, the tools available can sometimes hurt more than help. Thing is, bad eq's are bad eq's. If you just have some junky dbx 266 compression piece of crap, you might as well not have a compressor. Avoiding all that stuff removes most of what can contribute to horrible audio.
Okay, I have covered the gear part. Unfortunately, that is the LEAST of your concerns!
As Shailat and Slackmaster have suggested, it may not be as much your tools as HOW you use them! I wrote some long ass thread long ago that pop's up here and there that covers this. It is always best to do a "faders up" mix first to hear EXACTLY what the problem areas are BEFORE you start twiddleing with stuff! Do the best mix you can without doing anything other than adjusting volume and possible panning some things and see what it sounds like. Since I wrote that thread long ago, many guys have emailed me stating how their mixes sounded better than the mixes they spent days working on with a bunch of unneccesary processsing.
Like Slack, I went thought a period when I switched to digital mixing where I used as little processing as I could. At the time, I didn't have very good digital mixing tools, and it seemed like anything I did with them made things worse. Now I am back to using more processing, but have a much better handle on what works. I also have better tools to work with.
I agree fully with Shailat about the fact that you need a FIRM understanding of what your tools will do for you. Forget all those suggested settings you read. Anybody posting crap about how to "set it this way to start" is either too lazy to explain just WHAT a eq or compressor will do, or doesn't have the foggiest idea themselves!

I could go on for hours about the differences between putting an eq before or after a compressor! I would lose you quickly in that conversation if you didn't fully understand what both are doing and how they relate in a musical context.
Things you really need to understand!:
Gain structure and dB scales
Fletcher/Munson Relative Loudness Curves
The basics of what equalization is and the different TYPES of eq's and what their controls do
The basics of what compression does and the different TYPES of compressors and what their controls do
A laymens understanding of acoustics (even a laymens understanding is proving to be a LOT of reading.....)
With these basics, you will hear audio in a whole different way! The approach you take towards audio production will be totally different than it is right now. You will make much better decisions while tracking and mixing.
Good luck.
Ed