Time investment is basiclly non-existent. I havent been in game much at all recently, only to change skills and take down a 1 billion isk carrier
, completely ruining someones day! Your skills train in realtime, and do not stop training when you log off. So bascilly its log in, set a skill to train. (it will train to completion, unless you switch it. And if you switch skills while they are mid training say .. it's 50% done, you don't lose what you have already trained so you can come back to the skill at it will continue from 50%.)
The only real investment you need to make is in aquiring isk (cash). Which is really easy once you get your self into a good ship. Just realize that your not gonna be able to fly alot of the bigger ships off the bat...but that doesn't mean you can't have fun. You can have just as much fun in a fast frigate squad as yuo can in a battleship fleet, probably more.