I love my linkshell. Yar....
However, I'm not the leader, nor a pearlsack holder, so I can't speak for adding new players.
Also, I somewhat object to the generalization that below level 40=newb.
I'm level 20. HOWEVER, I could easily be level 40 is I wanted to, instead, I decided to craft and quest. So I'm a skilled crafter with an excellect cash flow, and I constantly read up on the game so I'm able to help upper level people with questions.
I'm a crafting guru, and a leveling non-newbie, but not necessarily super knowledgeable.
I know, I know, there are exceptions, but I felt like getting on my soapbox. ^^
I hope you find a good linkshell. My advice would be to just help other people...that's how I got invited into mine.