You get one remap / year. When you use it, the game will warn you that you won’t be able to remap again for a year. But if you click ok, your character sheet will say “Next available remap: 364 days 23 hrs 59 min etc. Bonus Remaps: 2.” And a [Remap Now] button to click. The button will disappear once you run out of remaps.
There are no known sources of remaps; once you’ve used the 2 bonus ones, that’s it, you’re down to the yearly one.
In order to cope with the yearly one, if you look at the skills, they fall into 3 broad categories:
Int / Mem - Engineering, Armor, Shields, Rigging, Industry, Science - basically support skills and industry skills
Per / Wil - Spaceship Command, Guns, Missiles, Drones - ship and weapon skills
Other - a few groups involve charisma but they don’t have many skills in them
For the first year, the best choice is to keep the even-spread remap and just train whatever you need; if you try to stick to int/mem or per/wil, you’ll get bored and/or make yourself sit in station cause you don’t have the skills, and end up hating the game.
After the first year, it’s possible to train up support skills for a year, then ships and weapons for the next year.
EDIT: Also, the formula is you get Primary Attribute + 1/2 Secondary Attribute (as listed in each skill you add to the queue) of skillpoints per every 2 minutes (for Alpha, per minute for Omega). So before you do the remaps, you can figure out what the effect will be. Typically it’s 10-15%, so in a month you gain 3 days.