This is the space I have designated for the Societies page of my Individual Hypertext Assignment. Technical societies can be a great asset to a student getting ready to journey out into the professional world. They give exclusive member only seminars, job listings, contacts, and mentors. Even experienced professionals can benefit from becoming a member of a professional society in their trade. It even looks good on your resume if you're an active member of a trade organization. Here's a few excellent societies for the Business & Technical Writing field.

Societies

Society for Technical Communicators: This is a very well known and respected tech writing organization. The members are mostly made up of writers who deal with the more technical subjects and primarily write things like user manuals, online help files, software documentation, and that sort of thing.
Pros: Massive networking potential, exclusive job listings, huge database of experienced professionals in the field to offer support
Cons: Membership fee

The International Council for Technical Communication: INTECOM stands for international co-operation between technical communication organizations. Their aim is to improve technical documentation and communication around the globe. Their main focus is international documentation, which is pretty interesting since it deals with cross culture writing.
Pros: Networking potential, huge database of Technical Writers, helping improve international Technical Writing
Cons: Membership fee, not as large as the STC, international writing (if you're not interested)

The American Society of Indexers: This is a really specific and technical organization. Their focus is on database building, and indexes. They claim "ASI is the only professional organization in the United States devoted solely to the advancement of indexing, abstracting, and database building", which is usefull if you're into that sort of thing.
Pros: Highly specialized technical society, contacts of people in your specific field, the only society in America devoted to indexing, abstractions, and database building (according to them)
Cons: Membership fee, highly specialized, really technical (if you're not into that sort of thing)