Hey there! I was married at Now Jade last year. We spent about $15,000 for the two of us and our immediate family (with everything all together - flight, wedding package, dress, suit, decor, photographer, DJ, etc) and our guests paid their own way and rooms. I think you can contact either the hotel or a travel agent. I personally went straight to the hotel wedding coordinator to book, but my friend used a travel agent for her wedding. So, I don't think it matters. A travel agent might be easier to arrange flights and stuff too though. We did that part on our own.
First step, research your resorts and book. Next step find your photographer/videographer. Our photographer created our wedding day itinerary for us and gave us a lot of advice. It really took a lot of pressure off. We used Bohemia Photography, I was very happy them. I actually just got on here to review them, I didn't know this site was here for my wedding (which would've been nice)! Their website is www.bohemia-photography.com
Best of luck to you! And just remember, nothing is ever perfect, so just go with it!