I would say that the best education you can get is hands on. you can only read so much, and unless you can read it, then take what you've read directly underwater and shoot, its really not going to help you much 2 months from now.
My suggestion is to grab a pile of laundry (big pile, nice and high. Shouldn't be too hard if your house is anything like mine) pile it up as high as you can, then get some bright, but small childrens toys and scatter them throughout. now make the room your in fairly dark, lots of window light at mid day, but no electric light. This is your "underwater reef" simulator ;D
Its always "low light" conditions under water, so you'll have to rely on your flash. you'll always be shooting low to the ground, and the bright fish will always contrast the not so bright rock. You'll probably notice right away that on camera flash isn't going to give you the "professional" shots your looking for. it shouldnt be too bad though.
use your reef simulator to try and compose interesting looking shots. Learning proper composition is going to make or break your imaging (land or sea) You'll also notice that you're going to end up with images containing a lot of grain. This is because your camera will need a lot of ISO to get the shots in low light.
As far as settings and technique go. Trial and error has always been my best teacher, with your reef simulator and the zero cost of digital imaging, go crazy. try everything, see what works, and what doesnt. You'll learn a lot faster this way than reading in a book. when you've done what you can with the simulator, read the books, you'll probably understand them a lot more now, and be able to use them to try ever more interesting things in your "simulator".
Also, find interesting shots that you like online. then try to get a similar picture in your simulator.
Hope that makes sense!
What part of the phils are you planning to visit? I'll likely be in Cebu April through May myself. Great place for diving
