Okay, I know this is not the site for this type of question, but...if any of you ever took a statistics class, could you please clarify something for me?

In regards to random sampling, how should I figure out how many number figures I should skip? I read in a textbook example that it was determined by how many numbers were skipped from the beginning of the random numbers table until one was found which was not too large. What constitutes a number being too large? Is that in comparison to the total number out of which random numbers are to be picked? Also, if the row of numbers I randomly picked turns out not to have any numbers which are too large, then how would I pick the numbers randomly? Could I just pick the entire row in that case?

I'm trying to complete a project for my class, but I'm totally lost on this one.