If I see information which I feel is important, is it appropriate to make that text bold so it is noticeable?
Most of the time no; it is common to highlight important terms the first time they are met, but we don’t tend to highlight whole sentences unless they are really vital. Usually all of the text is important, otherwise it wouldn’t be there.
You can use the Note style for information that is unexpected or not obvious from the preceding text. The Note style is created by a block-level CSS class, so the text you apply it to should be a whole paragraph.