Whatever you do, do not use cruises-n-more! They might seem like a good deal but then they have a few hidden surprises. We booked a cruise through them in July for February because they seemed to offer the best price. However, a few days after we booked we found out I was pregnant and would be too far along to go on the cruise as according to regulations you cannot be over 26 weeks pregnant to cruise. Well they charged me a $75 cancellation fee for a cruise that I was no allowed to go on. Not to mention, they sneakily added a $29 membership fee that my cc company gladly reversed but couldn't reverse the cancellation fee as they made me sign a form or else they wouldn't cancel the cruise!
Anyway, I would recommend ecruises (they give you free insurance) and vacationstogo (they have a 90 day ticker of last minute cruise specials).