yeah it just means to move in the direction of the punch so it doesn't hurt as bad.
you should look into leg kicks. a pushing kick and a round kick. that'll greatly expand you stand up game since you already box. i think stickgrappler.tripod.com is a good place to get some info on muay thai combos and stuff like that.
a great place to go for submission grappling is bjj.org. the only problem with that site is most of the techniques they show use a gi, which most mma fighters seem to not like. i don't realy like them personally. just imagine how to make them work by grabbing their body and not a gi. That'll help your ground game.
i guess the only thing you'd be missing is throws, takedowns, and clinching. also some general info and terminology on ground work.
i got into mma about a year ago and i love it! so if you have any questions, even if they are really open ended, ask because i'd love to try to answer them.