rep points, don't mean to much in the long run, it's more about how helpful and knowledgeable you are, and you seem to be both so keep up the good work.
Don't be embrassing if you don't have much rep, but it comes, eventually, and its not realy working right.
When a person sees a helpful post sometimes they click on the scale thing by your post and either give you positive or negative reputation. Positive is green in your usercp and negative is red and neutral (or, at least I think its neutral) is grey...