Exercising with the Ball

ASSI - I am still trying to understand how to properly use the exercise ball instead of coming with an instructional poster it should come with a trainer. I use it but wonder each time if I am using it correctly, I even question if there is adequate air in the ball. The Exercise Ball came with a pump that inflates and deflates and a measuring tape to prevent over inflating but the tape that is supposed to exactly measure the width of ball can wrap around the ball twice; therefore, it defeats the purpose of ensuring proper inflation. I am uncomfortable using the ball but I like the various exercises that can be done using the ball. I would enjoy it more if I knew that I was performing the exercises correctly. Nonetheless, I continue to use the ball three to four times a week for the last three to four weeks. My biggest problem is storing the ball it seems to be in the way with every move that I make. It was placed in the closet but each time I went into the close I had to remove the ball, it was in a corner designated as the exercise corner because it contains a weight bar, free weights, and the small ball weights but it often rolled out of place and into the walk space causing me to roll it back each time I walked towards the kitchen. I have a desire to deflate the ball after ever use but it took to long to inflate and then what will I do with a flat ball that resist being folded. I actually without tension on my back when I do sit-ups but feel like I am straining my neck.