For whatever reason, the cruise section on FT has always been extremely quiet. I suppose most of the people who take cruises regularly prefer cruisecritic.com or some more niche forums focusing on one particular cruise line.

In terms of booking, the main options are:

1) booking via a large (online) travel agency such as Expedia, AAA, Costco - which may offer discounted rates or additional amenities; deals seem to be most common for the entry-level cabins (inside staterooms); and you obviously shouldn't expect much in terms of customer service or advice

2) online travel agencies which rebate part of their commission; with most cruise lines offering discounts is a severe contract violation, but some agencies still engage in this practise

3) a reputable travel agent affiliated with a major consortia (e.g. Virtuoso, Travel Leaders Group etc.) who would hopefully offer some decent advice, and in addition often can arrange additional benefits such as onboard credit, drinks packages, spa treatments etc.

The more high-end the stateroom and cruise line, the more likely a good TA will be able to arrange additional benefits.