Yeah, ASAS is crucial, whether you are a noob or not. The best place to put it is either on the lander stage, or directly under it, so that you have it for as long as possible. It helps immensely on lander stages, because you'll want very precise control for maneuvering, and ASAS will allow you that.
The best way to get a Munar orbit, if your rocket is roughly in the same league as my Spaceboom: Go straight up, start veering right at around 30K, gradually increasing tilt so that at 60K you're flying parallel to the ground, i.e. straight at the "horizon" on the navball. Keep going in that direction, bring up the map and the map-navball, and look at the orbit display. You may want to roll so that the "ground" on the navball is below, but keep pointing at the horizon. Look at the orbit from the side, adjust course if it's going too far above or below the plane of the Mun's orbit, and keep going. Keep going until the orbit begins extending out, and start managing your throttle. You want the tip of your orbit to be within a hundred kilometers of the Mun's orbit. Cut throttle and wait. Then, it's all about luck and/or timing. If you're in luck, the Mun will catch you on the first pass, but if not, then there'll be more maneuvering involved. At the apoapsis of your orbit, point prograde and accelerate. You'll want to reach somewhere around 550 m/s, but if the Mun is significantly far ahead or behind, you'll likewise need to be going slower or faster to meet it at some point. Once you're there, cut throttle and set maximum warp. At some point you'll meet the Mun, and unless your luck is terrible, you should be in a pretty wide elliptical orbit in it. If your luck is terrible, you'll be heading straight into it, in which case point your rocket into the horizon on the navball (it'll be the Mun's horizon), and accelerate until you have an orbit.
If you want to actually land though, heading straight into the Mun isn't so bad. Point your rocket up and gradually decelerate, keeping in mind your fuel reserves and descent rate. If you're going sideways too fast, you might want to point retrograde instead (at the yellow X-circle on the navball), or at the horizon directly under the retrograde marker until you are falling straight down. At about ten kilometers' altitude, your descent rate shouldn't exceed 300m/s, and depending on how heavy your lander is, you might want to start being paranoid about how quickly you are falling. Keep slowly decelerating so that at four/three Km you're only falling at 100m/s. Set thrust so that that speed remains constant or decreases slowly, and at 1000m or so increase thrust further, keeping the falling speed ever so slightly above 30m/s. ASAS is incredibly useful here, as it'll allow you to make minute corrections to your drift. The actual height of the ground varies, so at 500-400m extend lander legs, slow down to 10m/s and watch the ground approach. Even though the legs allow landing with more speed than usual, they are still prone to breaking sometimes, especially if you drift. If you see that the surface is a slope and you think your lander might fall over, bump the thrust up slightly so that you hover (be careful not to fly too high up), and nudge the rocket (with ASAS on) away until you find a spot where it's level. Then, again, nudge the rocket so that your drift stops, and slowly descend. Then do a victory jig, and, if your lander still has enough fuel, fly up, fold lander legs, point the rocket at Kerbin (big purple squareish crosshairs on the navball), and keep your fingers crossed. I haven't quite figured out the proper way to correct for gravity or orbital drift when returning (which is why of 18 days of my latest Mun mission, 12 were spent on a ridiculously long trip to the outer reaches of the Kerbin's planetary system, so that I could decelerate and fall back to Kerbin with what little fuel I had left), but looking at the map and the orbit vector should be a good way to tell where you'll end up going. In any case, your primary task is getting out of the Mun's SOI, at which point you'll be able to slow down and fall back to Kerbin. And that's pretty much all there is to it at the moment.
Thankfully, despite taking 12 days longer than necessary, the crew returned to Kerbin safely. But the Lander didn't survive. Again.