The biggest problem with you routine is the number of times you do it. You do not want to lift for any specific muscle more than twice a week, it is simply overkill. More importantly, you are training for cross country, and running the mile I presume. The routine you have will most likely not help you at all. The weight you are suggesting is not a lot, so you will not have to worry about bulking up, but it will take time away from more important things like running more miles. However, if you really want to incorporate some lifting into your training then this is what I suggest:
bench 3x20 at whatever weight you feel comfortable
4x5 pull-ups working your way up to as many as you can do
4x5-10 dips again working you way up to as many as you can do ( this is a very important exercise for strengthening the shoulders, triceps, and back)
pushups are also key. I like to do a lot of pushups right before I start running and then just as many immediately after my run.
I think the most important thing for you to focus on though is core work. IMHO building a strong core is key to running success.
-keep your sit-ups routine the same (if you can do the sit-ups on an inclined bench to really get maximum benefit)
-do 3x30 leg raises (where you lay on your back and lift you legs straight in the air and then back down again, leaving six inches between your feet and the ground)
-and 3x1:30 abs bridges (these are great because they train your abs to stabilize your body.)
-leg holds are also key: lay flat on your back and hold your feet off the ground about six inches. Hold them there until you can no longer take it, rest, repeat.
you do not need to focus on shoulder biceps, because well when was the last time you saw a great runner with no neck and massive biceps? Best of luck and lastly remember to stretch before and after you lift. Stretching after you lift is key to maximizing the effect of your routine, it helps blood flow to the areas worked and maximizes recovery.