Wow, thanks. I'll delete it right now and let you know if that worked.
It may well help, but it may not solve your problem. The issue you're confronting is a common one, especially for a new user who is excited by the prospect of downloading a bunch of apps when they first get their phone.
For such folks, I'd recommend the following.
() Use your phone in a completely stock state for a couple of weeks. Don't add apps. This will give you a "baseline" in terms of experience to which you can compare performance as you add features. And for God's sake, don't root your phone, at least for awhile.
() If you're using your phone for email, as you probably are, explore your options for various email clients. Make sure things are working well for awhile. Again, this usually takes a couple of weeks as your use "piles up."
() If you are messaging, see comment above about email.
() Once you've become accustomed to the way your phone works, add apps carefully. Be especially cautious about apps that "synch" on a regular basis. (e.g. news/weather/etc.) Feel free to add such apps, but give each one a day or two to operate without other changes to give you an idea of any impact they have on performance or battery use.
() Strongly resist adding ANY automated task killer. On the other hand, you might try adding an app like "SystemPanel" that can be used to kill tasks if necessary, but mainly let you know what is running on your phone so you can learn more about its operation.
() This will all take some patience, a virtue often lacking among those with new phones and among those who haven't grown up. Cultivate it. In a couple of months you'll be very familiar with what works and what doesn't on your phone and you'll have developed a degree of patience that is very useful in other areas of your life.