You think you guys have got it bad, I can't get to the Mun without building stupidly oversized, over powered rockets and that's in sandbox mode.
Career mode, I completely suck at
This is one of those times to remember that bigger is not always better. If you can get into the upper atmosphere in two (preferably one) stages, then you should be to get to the Mun relatively easy if you know how to do the correct transfers to achieve an orbit and raise the altitude to intercept.