Hi LogicPro baby step!
& Welcome to the forums :)
There are a couple of things you need so that you can connect your keyboards to your Mac.
1. A MIDI interface or a simple MIDI to USB device. I believe M-Audio and Motu sell economical MIDI interfaces. You'll need at least 2in and 2out (one for each of your MIDI synths).
2. Another good idea is an audio interface. This will enable to you take the audio output from the MIDI keyboards into Logic... because MIDI is only instruction or numerical values that trigger the sounds of any MIDI instrument. The audio or sound that comes out of the Triton needs to be routed into Logic if you want to hear the Triton's audio through Logic.
I wouldn't be able to recommend an audio interface without knowing more about your needs (e.g. do you want to be able to record multiple instruments/band members simultaneously), budget, etc.
Some audio interfaces also act as MIDI interfaces too :)
Once you have a MIDI interface you can connect it to your Mac and download any drivers (if needed and recommended by the interface).
Personally, as Logic can have a 'steep learning curve', I'd recommend learning a bit about Logic first... or even start with Garageband.
For Logic, I'd highly recommend watching the Logic 8 101 tutorial:
Or check out the Garageband tutorial on our tutorials page too.
But let me know when you have the abilitiy to connect the MIDI keyboards to an interface and your Mac, and if you need any help at that stage.
Hope this helps