Its helpful to put what Timezone your in, that way you can hook up with a linkshell that's active when you are. I am in an odd place @ GMT+3, so I play with UK/EU people mostly. Causes me a little more lost sleep than normal, but thats ok today.
Richard or PosterChild is correct, also some LSs can focus on Social, Crafting or Ranking Up/End Game so by explaining what you're looking for you get a more targeted response.
Of course you can actually look up the list of LSs available on top and do the work yourself...