stick to the basics first.
proper gain staging is a must, especially if you also record (vox and/or hardware otb). y'know the sayin', can't shine a turd. so getting that right is the first hurdle, usually overlooked and forgotten (hence the overuse of compressors and limiters in order to control the peaks as opposed to using it as an effect for flavour and sound) just like the other important aspect, signal flow. signal flow in the daw world can be real simple or as complicated as otb, and is really important to overstand if you're doing a hybrid, itb and otb together. don't jump into the more unique routing and methods (i.e. sidechaining) until you learn the basics and definitely not until you know your daw and set up.
once that is tackled, doing simple listening and training your ears,as well as referencing (especially on your set up but also hear what those references sound like a a treated studio to hear what you might be missing, although they also might have a less than stellar monitoring and treatment). while doing that, treat your room within your budget and with research, i don't expect people to get into absorption co-efficients and the many and ridiculously long formulas but just an overstanding that just place shit on the wall, with no air between it and the wall, isn't the proper method. knowing the deficiencies that can't be fixed or may cost too much and finding ways to compensate, sometimes it's just by knowing what steps you have to do after referencing your mix at places that have good acoustics. of course, good monitors and placed right.
stick to basic plugs in order to learn the tools. there are different types of eq's and compressors (and other dynamic processors), getting bogged down on fet, feedback/feedforward, linear phase, or worse, esoteric controls some of the good shit, both hardware and software, will muck shit up. learn about the problem freq's and freq build ups, masking, etc (the mixing engineer handbook is a good book to learn, as well as, the recording engineer handbook). once you get the basics and a feel on how you like to work, get to know the differences in the types of processes, while looking for the tools that you like sound and feel-wise.
same for time based processors
check youtube, certain dvd tutorial vids, maybe golden ears for freq ear training but shit is hella boring, books (i'm supposed to start reading the highly rated 'mixing with the mind) and vids specific to your daw and overstand that learning never stops and changes with the tech (even pros don't have a set comfortable way to deal with mp3 versions, some are treating it like a whole new format, like they had to when going from vinyl to cd, where a simple conversion isn't the best solution)
one thing, i like mixing and i see it as a total separate process but the times have changed, at least for beatmaking, where you're expected to make a good mix when looking for placements, but if you don't take a liking to it don't make it cut into the beatmaking creative time, which it will do to some extent.
also know, the same people that expect a good-great mix from you on your beat cd or submission tend to listen to shit in the worst places, go figure.
shit, that was long, it was supposed to be just the 1st line, lol