Have a look at how an "Asparagus" rocket works and practice getting into orbit.
This is a simple Asparagus setup;
The key here is the FTX-2 External Fuel Duct
. It is critical that this is placed correctly. The Fuel Duct is directional and forces fuel flow from point A to point B (A being the first placement and B being the destination placement of the tube)
I'll assume you know about staging. If you don't, go do some tutorials
Begin on the Launch pad;
- Set your SAS to 'ON' (default=T)
- Set your thrust to MAX (default=SHIFT)
- Fire your rockets and power-burn until the 10km mark.
- Turn off SAS and start your gravity turn - Look at the NAV ball and push your rocket over the 90 degree heading (it's easier to go East as you will be working 'with' Kerbins orbit)
- Initially, set the nose to the 40degree inclination
- After a while you can try pushing your rocket futher over towards the horizon. As long as you are climbing you can keep the nose close the the horison
- If you look at your map you will watch your Apoapsis (Ap) grow.
- You should start to 'level out' (by pushing your nose BELOW the horizon mark)when your Ap reaches about 100 km and increase your Periapsis (Pe) to about 100 km
- Cut your engines - congratulations, you now have a stable orbit
To get to Mun you need to perform a "Hohmann Transfer" Essentially, it's just a case of getting into a circular orbit and then burning prograde untill your Apoapsis intersects with Mun.