Sports focusing with rebel xt-help

I shot some pictures at a little league tourney and posted them in the sports section here.
During bright daylight I was having a terrible time getting crisp images w/o blowing out the colors.
Every shot seemed a tad OOF and I tried thousands of combinations on settings, I was handheld so that probably hurt but I was braced against a pole and was pretty steady.
Is there possibly a setting I may be missing or a focusing technique I should be using?
I'm very new at this, so please try to use simple terms for my simple mind

I also posted some night shots, those were the only keepers of the night out of 38 photos

Oh, I was using the 70-200 2.8.

While I am no expert, or even close to being one, I think we need a bit more information to answer your question. However, here is a start.

Being new to photography myself, I would probably start off by shooting in the "sport" mode. All the settings there are optimized for this type of application.
If you shoot in one of the Creative modes, try the P mode, set the ISO a little higher than normal, say 200 or 400, use AI Servo mode. Experiment. The great thing about digital photography is that you get (almost) instant feedback. I say "almost" since the LCD screen is small and not very bright, so you may not really be able to get immediate feedback outdoors in bright sunlight.

Here are a few thoughts that may or may not help:
--On the night shots, the ones you posted are quite good. Since action shots are tough at night, concentrate on the type shots you posted where there is a stop in the action. That would include the batters waiting on a pitch, fielders in a ready position, the pitcher prior to his windup, etc. Also, it's digital so why did you only take 38 shots? I can and sometimes do take 38 shots in an inning. One thing that I had to force myself to do when I first started with digital is to take more shots. You can always delete extra shots when the game is over but you once the game is over you can't go back and take more photos.
--On the daytime photos, the two shots you posted were a 2.8 and a 3.5 shot. In theory they should still be in focus but your depth of field is very small at those openings. I think a higher ISO setting to allow for a higher f-stop might have help in some cases. I am guilty of trying to push my lenses to the limit when I might get a better shot if I would consider various combinations. For example, the photo of the stationary fielder didn't need a 1/640 shutter speed so you could have shoot at a slower speed and a higher f-stop.
--I do have some question about the light in the daytime shots. Based on the settings (and the shadows) it looks like it must have been around dark. If you have the time, look at the the photos in my "F_L_E" gallery listed below and there is an album there on Madison Central baseball. These were all games at games last month that started at 5pm with no stadium lights but even so I was able to shot just about everything at 1/1000 and I got plenty of light. The shots aren't all great but it may give you some ideas for your photography at games. Good luck.

Frank.

No. On P&S digital cameras you can use the LCD to judge the quality and exposure, but not on Canon dSLRs. The LCD gives very backlit scene. Almost every beginner complains that images look good on the LCD but are all dark when downloaded. The your only use of the LCD in the field is to see what you recorded and the histogram. You cannot use the LCD for exposure by image.

Amen to that. I shot a whole batch of underexposed building/sky shots when I failed to understand the exposure lock prodecure. Based on the LCD, I thought my shots were all perfectly exposed. Now I understand why people are always talking about needing to check out the histogram.

Frank.