After a new golfer learns how to swing a club reasonably well (getting it on a good plane/ proper weight shift/ proper release of the club, etc.), they will find that the biggest challenge becomes making good contact with the ball on a regular basis. Getting the clubhead to contact the ball right on the sweet spot at the exactly right moment is not something that comes easily for most beginning golfers, regardless of how pure their swing looks or feels (and it's no wonder, there is very little margin for error, especially with the less lofted clubs).
The clubhead must not only navigate the perfect path through the contact area, but it must also contact the ball at the appropriate moment during the downswing (excluding the driver which we hit slightly on the upswing). Additionally, the face of the clubhead must be perpendicular to the target line at the moment of contact. Timing is crucial.
Most of us that have been golfing for awhile got a good feel for 'solid contact' simply by hitting thousands and thousands of range balls and playing hundreds of rounds of golf; thereby getting the feedback we needed to groove a repeatable swing. This can be an incredibly frustrating way to learn the game because in the beginning the bad shots outweigh the good ones disproportionately. One starts to get discouraged quickly, especially considering how expensive range balls and rounds of golf are. It's no wonder that so many people give up the game (or just stick to Wii golf). Fortunately, there is an easier and faster way.
First of all, if you've never played golf, or you really don't know the fundamentals, you need a series of lessons in my opinion. The setup needs to be in place before moving forward (proper grip, alignment, stance, posture, and ball position), and then you need to learn how to properly swing a golf club (getting the club on the correct plane/ making a good shoulder turn/ firing the hips/ keeping the head and spine still/ getting the body weight to the left side of the body on the downswing, etc.). You could learn these things on your own, but it's gonna take awhile! I think it's well worth the money to have an instructor guide you at first just to get down the basics. After a comfort level with the basics is achieved then the challenge becomes building a repeatable swing that gets the sweet spot of the clubhead on the ball and traveling through the ball on the right path.
Here's the drill for accelerating the process of building a repeatable swing:
Find a lawn or park where you can make a full swing with a golf club. Place two golf tees in the ground about 8 inches apart (white or yellow tees work best for this because they stand out). Take a pitching wedge, and swing the club so that the clubhead brushes the grass between the tees. As you do this, make sure that the clubhead brushes the grass *right between the tees* and not before or after the tees. That's it! By doing this over and over, you will build a repeatable swing that will help you hit golf balls on the sweet spot of the clubhead, and at the correct moment of the downswing, more consistently (best of all, it's free, no golf ball or golf course required).
As you improve with this drill and find that the clubhead of the pitching wedge is brushing the grass right between the tees every time, then move the tees closer together and try and get the clubhead to travel through a narrower gate (and so on and so on until the tees are so close together that the clubhead will barely get through without hitting either tee). Then, start moving towards the less lofted clubs in the bag, ending with the driver (repeating the same process with the tees).
This drill really requires that you pay attention to what's going on. If you notice that your tendency is to brush the grass well after the tees, then you probably have an issue with topping the ball. If you brush the grass before the tees, then you probably hit the ball fat more often than not. If you notice that your clubhead regularly hits the tee furthest away from you, then you likely stand too close to the ball. If you hit the closer one regularly, you stand too far away.
Also, be conscious of the path that the clubhead is traveling on as it brushes the grass between the tees. If the 'brush' of the grass points excessively to the left, you are probably either pulling or slicing across the ball. If it points excessively right then you are pushing or hooking the ball. The goal is to get the 'brush' going straight at the intended target. Noticing the direction of the 'brush of the grass' may sound difficult, but it's really not if you keep your eyes down after the clubhead moves through the grass (which also helps with keeping the head still until well after contact, also incredibly important).
The more you do this drill, the quicker you groove a repeatable golf swing. Good luck and have fun!