In addition to watching I would suggest following these websites:
enuhito goes to pretty much all the major shows live. Translates a ton of stuff. All the big news you can get in English here.
Go to place for all of your Dragon Gate needs. Detailed information about all of the current angles. In English.
Everything you want to know about DDT. English.
Good place for New Japan information. Forum has info on all of the other promotions. English.
My favorite blog. Just tons of info. Only person who loves laughter7 more than me
In Japanese but you can get the general idea of things by running it in a translator.
Tokyo Sport website. I already linked you to the wrestling section. Japanese.
SportsNavi site. Tokyo Sport is better but I figured I would link it anyway. Japanese.
List of twitter accounts of the New Japan wrestlers. I don't think everyone is listed (off the top of my head Suzuki and Sakuraba aren't listed) but it's a pretty complete list.
Yottsume translates stuff from the live shows. Also does translations of videos on youtube.
Here's the twitter accounts of the promotions:
I don't think Dragon Gate has a twitter so follow CIMA
or follow their facebook page
I don't think DDT has a twitter so
I hope to hell I was allowed to post all of this but anyway if you are serious about wanting to get into puro this is a good start.