I'll briefly touch up on a few recommendations for periodizing your strength.
One- If you haven't already done it, you need to consider a transition phase. Since you are a college athlete over here, I'm assuming that your outdoor season ended about 2-3 weeks ago, depending on how well your did in playoffs. You need about 4 weeks of transition here. If you haven't started already then you need to get moving. By transition I mean that you must use the next few weeks to compensate for a long season. Don't abstain from training, but only go to the gym 2 times a week, and use a few other days to play some other sport. I'm not going to make cross-training recommendations here, as I see the most important aspect being, you, enjoying yourself. Don't underestimate the importance of this phase, as it will affect you greatly over the next 6 months.
Two- Anatomical adaptation phase. Use 3 - 4 weeks to prepare the muscles, ligaments, tendons, nervous system, etc... You may wish to use a Upper/ Lower body split for this phase. It is what I've seen the most success with. For this phase you're not going to go over 70% of a one rep max in any exercise. And I would go as low as 40% and only rarely go up to 70%, for any exercise. Use a set x rep scheme of around 2-4 x 8-12. Don't go crazy here just yet, that's coming down the road very soon. Consider a medium rate of performance. Look at this as a sort of primer for the next three months.
Three- Maximum strength development. First considering that as a goalkeeper you're a very power dominate athlete. Power being maximum strength x speed = power. In other words to reach your highest potential power, you'll need to really capitalize on this 3 months of training to develop max strength. I feel that posterior chain should be your biggest point of concern. Obviously I'm not saying to forget the anterior part of the body, that would be ridiculous. But exercises such as Deadlifts, RDLs, Lunges, Cleans, Snatches, Bulgarian Split Squats, Good Mornings, Glute Ham raises, need to be the primary focus. (considering that you don't have any deficiencies) Your set x rep scheme will resemble this: 10-5 x 5-3. Maintain this period for 3 months.
Four- Applying all that strength and speed development into power. This is going to be another 1-2 months depending on when tryouts are. Here you're going to do what is mostly called dynamic effort work. You're going to use this gym time to really train your nervous system to fire at an efficient rate. Mainly you're teaching your body to fire large motor neurons(fast twitch muscle fiber connectors) to fire at an extremely fast rate. You're going to start using things like jump squats, dynamic upper body movements, and Olympic variations, more often during this phase. That is not to say that you won't need to maintain the strength you developed over that last three months, but it is not the primary focus anymore. Training your nervous system to be as quick as possible is. I recommend you look for dynamic effort information from the guys at elitefts, and over at defranco's site.
If you compare the speed plan which I outlined earlier, and the strength development plan here, you'll notice that they coincide. That's for a reason. You should consider using the plans simultaneously.