Welcome,
I've been here a couple of years and have not spent any real money. In my opinion, I recommend a hybrid wood. I use it to get out of the rough, and I'm in there a lot.
Regardless of which clubs and balls you decide to use, you must learn how to use them. This is true for the clubs you currently have in your bag. I use the avatar movement method to judge the distance on my shots. I found this easier to use than the percentage method. Either way you need to know how far each club will go. For me, I made a chart of avatar movements vs distance. This allows me to easily determine the distance the shot will go. I did this for all clubs in my bag. Of course this simple chart does not take into account the wind or elevation and that is left for my "feel" of the shot.
Main thing is for you to learn your clubs, then you can work on where to hit the shot.
As far as consistent sub-par rounds, putting is the most important part. Again it doesn't really matter which putter to use, as long as you learn how to use it.
Of course this is just one persons opinion. If you haven't already done so, check the forums for putting tips. There are several great ones with very helpful information. Granted they mostly deal w/distance but once you know how far to hit the putt, you can work more on remembering the breaks on each green.
Have fun and good shooting.