You can post in the official forums for guilds here>http://forums.elderscrollsonline.com/en/categories/en-pc-mac-na

Be sure to add:
what alliance
What server EU or NA
What type of guild you're looking for ( PvP, trade, PvE).
When you play, late night, etc.
Most importantly, what you have to offer to make the guild group better.

Finally, check out the guild websites, join them on Team speak and group with them. If they seem like a good fit, ask to become a member.

Note that most guilds (lately) do not care about applications and are looking for numbers. Also long time standing guilds are careful about adding new people so they don't unbalance the group that's already there. They won't advertise but you can join them sometimes by being available to group when they ask in PvP or Trials.
Good luck.