These are not all the guilds one might find throughout the realms, and all guilds may not be found in all areas, but this will give you a good breakdown of the most common guilds.
Spy Guild - Members of this guild make a living learning, buying, and selling information throughout the realms. This guild has no known home base of operations, and members can be found scattered throughout the realms, some of them in the most unlikely of places. Blackmail and seduction are among the favored tactics practiced by those of this profession.
Assassins Guild - The members of this guild are trained from a young age in the arts of murder. They are taught the foolishness of such emotions as compassion and mercy, and remain students until they have successfully killed their first target, and gotten away undetected. If they are caught, or identified, their instructor is bound by the laws of the guild to see them dead before they can reveal any guild secrets. If they are successful in their task, they're granted a new name. This is a secret name known only by members of the guild. This name will grant them safe haven in any fellow member's home, hideout, or camp for a single day and night.
Smugglers and Thieves Guilds - The members of these sister guilds are taught many things during their apprenticeship to a Master Thief or Head Smuggler, such as stealth, lock picking, climbing techniques, acrobatics, and other helpful skills. It is common for their members to work together on a regular basis, but that doesn't mean they trust each other.
Merchants and Shopkeepers Guild - These two guilds started out separate, but were so closely tied to together in nearly everything they did, that long ago they were joined as a single guild serving both groups. Two guilds as one, the merchants who buy and sell goods abroad, and travel perilous caravan routes, and the shopkeepers who help them to readily sell to locals.
Bankers and Tax Collectors Guild - This guild holds great wealth, and in some regions, great power. It's members are not always highly respected, but they are often given way to simply because of the nobles who employ them, or the institutions to which they belong. Members apprentice for years under a Master, who is often a very rude and pompous individual, in hopes of earning the gold sash of this guild.
Theater Guild - Members of this guild include dancers, musicians, actors, actresses, mimes, puppeteers, storytellers, and others who have devoted their lives to the entertainment of others. This guild is also divided into a number of subguilds run by appointed guild agents, such as the Storytellers Guild.
Artists Guild - Painters, sculptors, wood carvers, poets, orators, and even toy makers, are members of this guild. They strive to bring beauty to the world. Whether through a painting, a statue, a beautifully-crafted verse or speech, or simply by giving joy to a child with a wonderfully-created new toy. The members of this guild find themselves welcome throughout the realms, and often honored guests in the house of commoners and nobles alike.
Scribes Guild - Scribes record the history of the realms, among other things, with the written word. They are generally taken into apprenticeship at an early age and educated by their teacher. Then, on reaching their eighteenth year, many are indentured to a well-to-do, good family for a time. The money they would have earned, were they not indentured, is given to their teacher to help support their future endeavors, and help them to survive.
Master Craftsmen Guild - This is the largest of the realms guilds, and has offices in every major city. It includes stone cutters, masons, carpenters, and other construction professionals. This guild encompasses a large number of professions, and as such, has a number of local chapters run by guild lieutenants. Such as the Masons Guild, Carpenters Guild, Leather Craftsmen, Stone Cutters, etc. This guild also includes the Shipbuilders Guild based in Vashdell City.
Textiles Guild - If not for the members of this guild, the people of the realms would most certainly be lacking in proper clothing, as well as being without curtains and other household adornments. Members of this guild are apprenticed to a Master at any early age, and may learn any of a number of trades, such as seamstress, clothe weaving, dying, and other things associated with textiles and products.
Physicians and Healers Guild - Whether learned at a university to finally earn the title physician after many years of study, or taught by a healer looking to pass on a lifetime of knowledge, the members of this guild find themselves welcome at nearly every door. They are the guardians of life, and are known for their selflessness in healing and helping others.
Practitioners of the Mystical Arts - This guild has a number of local chapters looked over by Proprietors. There are as many local chapters as their are schools of the mystical arts, but all answer to the main guild. Like the Warriors Guild, this guild is also based in Camira City, Camira. Shree, the Royal Sorceress, is the guild's chief Proprietor.
Mariners Guild - After years of life on the open seas, a group of old mariners decided they needed a guild to represent men and women like them. Sailors, pirates, swashbucklers, and the like all came forward and banded together, and a new guild was formed. Now, nearly four centuries later, the Mariners Guild is one of the strongest guilds throughout the realms.
Warriors Guild - Two silver swords crossing over a golden shield is the crest of this guild. Usually trained from childhood, these men and women are taught combat strategies, survival on the campaign trail, and combat techniques, involving both hand to hand and the use of weapons. They learn the care of weapons, shields, armor, and any animals they might possess. This guild is based in Camira City and has a number of strongholds throughout the realms where members may seek sanctuary while traveling or after a battle.
Pleasure Guild - When the men and women of this guild join a house, they are given a bejeweled bracelet or neck chain with the house's markings. This is an outward sign to any who might wish their services, telling them to which house they must go to make any arrangements to employ the one who has caught their interest. Not all in the pleasure industry are members of the guild, but those who are, can usually ask a higher price than those who are considered freelance. Guild members also enjoy the benefits of steady lodging, and if the house employs any, the protection of it's guards.