Research a dive destination you want to reach and that is realistically within your reach in the next year or two. One you haven't been to before. Dig into it. Read up on it on Wikipedia, travel blog type places, ScubaBoard, dive travel agency sites like Blue Water Travel, etc...
There are a number of places that are quite large, have many options within them, odd place names and require considerable research to make an informed decision about. Indonesia (I've been to Raja Ampat once), the Philippines and the Hawaiian Islands come to mind.
For something like this, create a Microsoft Word (or similar) document, given it a title, think of it like you're banging out a term paper for a class in high school. In Wikipedia you can find public domain or creative commons licensed maps you can copy and paste from the Internet into your document.
In this way, you can slowly but surely pull the disparate pieces of info. together into an organized, coherent narrative to inform your understanding of the destination.
This approach makes the most sense for more 'intense,' far flung destinations like the 3 I mentioned, but you can use it for more mainstream destinations as well. Cozumel and Bonaire are well-known mainstream Caribbean dive destinations, as is Roatan, but if you want to really get into making an informed decision about them, you can keep yourself busy.
My Research Notes from Planning Cozumel Trip -
My Research Notes from Planning Cozumel Trip
My Research Notes for Bonaire -
My Research Note For Bonaire
My Research Notes from planning a Roatan Trip -
My Research Notes from Planning Roatan Trip
Here's a possible task to take on that's bigger than it looks. Like Bonaire, Curacao is known for shore diving, but the road doesn't hug the coast as much, the island looks roughly half-again the size, some dive sites have an onsite dive shop and/or 'amenities' (and people often rent tanks there), so the Bonaire model of head out with a pickup with 2 tanks/apiece in the back doesn't seem quite as common, from what I read.
Or, perhaps you'd be interested in family trip options where baby sitting service is of such reliable quality that you and your wife could get away (I don't know whether she dives).
Perhaps you're interested in 'dive trips disguised as family vacations,' where you bring along a relative to keep your wife company and help with the baby while you do 2 tank morning dive trips, but you'd like places with '1st world' quality health care available in case the baby gets sick, and topside entertainments for the wife and relative. Key Largo, Florida, would fill the bill. I imagine Grand Cayman would, too. It may be a bit early yet, but some of those southern Cozumel all-inclusive resorts with sandy beaches might be good to know about.
P.S.: I live in the U.S., so my frame-of-reference centers on the U.S. and Caribbean. You're in Oslo, so I'm guessing the Red Sea liveaboards call to you more, as they're closer.
Or maybe you want a land-based trip taking non-diving family along, and want to take in some cultural attractions topside. Diligently researching a potential trip like that down to airfare, where to stay and eat, how to get around, etc..., can keep you busy for awhile.
