Thread: Help Get in Shape

Hi all,
This is my first post and I am filled with questions. Ok for a little over a month I have been working out everyday to lose some weight and get in shape for the summer. This is my current routine:
4x25 pushups (sometime 6x25)
4x10 crunches (sometimes 6x10)
4x10 reverse crunches (sometimes 6x10)
3x12 preacher curls 10lbs (sometimes I will rest then do
3x8 standing/preacher)
30 min on stationary bike low resistance (I usaully go 18-20 mph... its
the EMS grip pulse. It says I burn around 460 cal/150 f.cal but I
don't know how accurate it is)

I know this is a bad routine but it seems to slowly be working. Please make any comments on how to improve it but keep in mind that I only have two dumbells at 10 lbs (they are adjustable but i dont have other wweights yet). People have noticed that I am losing weight and gaining muscle mass though. If you know any other muscles I can work with only dumbells I am open to any input.
This is something that I really need help with: when I do crunches my stomach muscles could go on forever but my back starts to get tired/hurt... is there anyway to get around this? I am willing to do a lot... yoga, stretches, back exercises - pretty much as long as I don't have to make an investment. It is really interfering with my crunches but maybe I am just using the wrong form.
Sorry for the long noob post.
Coldsteel

Oh - I'm 16, 5'3"-5'4" and 125-130 lbs. I'm short and kind of chubby but muscular.

well because i have two 10 lb adj. weights my freind who lifts a lkot convicned me to try puttin all 4 on one bar... I didnt struggle but it was hard. i did 3x8 with both arms (a bit harder in the left) so i think i might stick with 20 now. thanks for the reply. i also upped to 8x25 pushups today (i should probably be doing like 5x40 instead maybe?). previous to today i had worked oput today but im going to start pushups/curls/bike(whats a good tricep exercise with dumbells and are there any exercises I can do for my back/shoulders?) one day and crunchs/rev crunches(maybe these new side bend things my friend mentioned for obliques)/bike the next. thats healthier, isnt it?

my main obstacle is still back pain from crunches. i need to find a way to work around that.