Listened to your "fresh" mix. Here's a couple of things I recommend.
Song choice is always up to the DJ, and doing a mix live for people is always going to be different than jamming out with your decks by yourself and recording it. That being said, one thing a lot of dubstep DJs do is let one track build and build, and right before it drops, switch over the crossfader quickly to the drop of the second track. This way all you have to worry about is keeping the two tracks in beat, and if you do it right, they don't have to be in key at all.
Another technique that makes all the difference is actually listening to your tracks and finding out which ones go together in terms of "key." What I mean is the song your mixing into is in the same key (A-sharp minor for example) as the song your mixing out of. This way you can layer the tracks and play them with both volume faders all the way up, creating your own mashup if you will.
I basically taught myself how to DJ with the help of a shit ton of online tutorial videos from ellaskins and others on youtube.
http://www.youtube.com/user/ellaskins#p/u
Watch his (ellaskins) videos. A lot of the mixing skills he teaches pertain to house related genre's but they will show you the basics about dubstep as well.
Keep in mind that dubstep is a 2-step genre even though the bpms are usually around 140. This means that the style of mixing that goes into hip-hop can be effective with dubstep as well due to it's 70bpm feel.
Lastly, just check out your favorite dubstep DJ mixes and analyze what they do to transition from one track to another. Every good DJ will have his/her own style and it's good to be able to copy and mimic what the big boys do, but eventually you'll want to find your own way of doing things. This will make you stand out from the rest of the pack, and will increase your hype considerably.
After that my friend, the sky is the limit. Practice practice practice, I put in 500+ hours before I felt my DJ skills were where I wanted them to be.