If you're worried about MPEG's rendering slow, you might or might not have a problem. MPEG's normally take a long time to render since every single frame has to be compressed. That time only increases with fancy edits. Now if your computer takes an abnormally long time to render an MPEG, say 2 hours for a 2 minute video, then you have a problem (which in that case may be low RAM or a slow processor).
As for recommended settings, it depends on what your wish to do. If you're making videos for your computer, it's not really neccessary to render frame sizes larger than 352x240, but that's just my opinion. Also, bitrates around 1.8 KBits should provide satisfactory results. What I would recommend is for you to experiment with the default templates and tweak from there to suit your needs. Remember:
Bigger frame size + More bitrate + More edits/effect = Longer render time + Bigger file size.