I haven't searched TOO hard yet, but most guilds are aimed at larger players. They require a DEC fee to join and/or every day/week (in order to build up the guild for one, and to keep the freeloaders out).
The benefits of a guild are great (discounts on new packs in the shop, but also bonus DEC for every battle). ... I was just wondering if there wasn't maybe some "incubator"-style guild aimed at those in the smaller (and most NB free to join).