try convertx2dvd. search it out on piratebay or mininova. It's a really dumbed down video to dvd converter. I say dumbed down because it is literally drag and drop, not because it doesn't work or something. It auto detects embedded subs and audio tracks in mkvs fine, as well as external sub files (like vobsubs, srt, etc)
It lets you pick and choose what streams or all streams or whatever you want. Usually it can fit 2 movies on a 4.7GB dvd+-r, but if you have a bunch of audio tracks, especially ac3 then it may not fit as much. It handles most common formats.