Right now, it would actually go faster than anything you've seen listed in this thread.
You get instant queues as DD right now (you already get insta queue with tank/healer otherwise) due to the influx of players and people filling the tanks/healers roles with DRK/AST.
Honestly, if you want to start/catch up it's now or never. You can catch up in a couple weeks considering decent exp is actually available for anyone up to lv 50 and exp is the only limiting factor otherwise.
It's easier than ever to complete various content (HM and EX primals) due to shitters having access to high ilvl gear easily.
Also, the storyline now grants you i110+ gear just for doing it.
Catching up is as simple as doing Main Storyline Quests right now.
Jump in while it's hot.
Regarding information, it's a bit of a vague question. Check the usual forums and the usual wikis. On top of that, make sure to check patch notes as they have good details in general.
The specialized websites are more designed around end game, if not end endgame and I only remember
one from when I quit over a year ago. I've seen other useful sites mentioned but I can't remember any of them.