there are many guild on druzzil ro that would suit your lvl, depends on what you want really, at 31 there is no point being in a raiding guild since you are 20 lvl's at least below proper raiding so i would surgest a guild like 'Final Heaven' which is a friendly guild, or if you are a lady one of the sisterhoods <roses and Thorns> would be good,
Final Heaven:- Sentyu
Sisterhood of roses :- Pummittz
Sisterhood of Thorns:- Roseworm
other good guilds that you could consider are Medieval Brethren, Semper Eadem, Unity of light, Souls of Armegeddon all of whom have a good rep.
I am afraid most of the other guilds i know are good have lvl resrtictions so would be out. but if you get up to 60+ send me a tell and i'll group with you and see if you would make a good member of my guild.