I'm old school and still like Robert Fenner's "Conscientious Marine Aquarist". Very basic understanding from reading about substrates, fish choices, filtration, lighting and more. The one issue I have with the book that it has been around so long, it doesn't deal with fishless cycling. Just ignore the part in it about cycling with fish. That's really old school but outdated.
Otherwise, it's a good starter book. Then IMO, hang out on the forum and ask informed questions, use other's experiences, plan your tank, and begin researching equipment options.
One other thing - FO and FOWLR are one in the same. Any SW tank worth it's salt... get it?
will have live rock for natural filtration anyway. For FO, I'd still think about 1 lb per gallon.
On the filter you asked about - that'll depend on what size tank, whether drilled or not (sump and skimmer vs. hang on skimmer, etc, etc). Get some plan on size tank first. What do you really want in there? Community or agressive?
Most of all - and to save a lot of money and headache... take your time. Plan.