Hey Nuno, welcome!
As for the official fan club it really depends on your own activity and how you want to use it...If you're looking for a place to just chat Maiden I would recommend staying here because the official forum is not more active with regards to Maiden talk...Most of the important news you can find on Maiden's Facebook or here...
The fan club is definitely worth it if you have plans to go see Maiden when they hit the road again. Maybe next year? Pre-sale tickets for shows, first to the barrier wristbands (if they still do those?) etc are very nice....Made it possible for me to be right upfront at the barrier in 2006.
The membership package could be better to be honest but when you resubscribe you get a membership Maiden t-shirt. There's also a 2£ discount for items in the shop so if you're planning to load up on Maiden gear it might also be worth it. The magazine you receive a few times a year covers the recent news and has interviews with the band and the crew, not always super interesting if you're a fan who checks the forums/maiden regularly, but a nice collectible item
Sometimes they do like video tours and diaries...but during "off time" like now, it's very slow around the FC. if I were you I would wait until more news around the new album is out and then join around that time...That's when things will pick up for sure for members.