At my work everyone has sql snippets that they use to answer questions. Some are specific to a customer, while some are generic for a given database. I want to consolidate those queries into a library/repository that can be accessed by anyone on the team. The requirements would be:
I'm interested in what has been found to work in other team environments.
You could use a wiki.
You could get started with something as simple as Tiddly wiki.
Rather than pasting SQL snippets, I would consider graduating to an ORM (Object-Relational Mapper) or some other library to make representing and manipulating the data easier. It provides a layer of encapsulation to guard against schema changes and a layer of abstraction so you can think of the data in terms of business logic (ie. a user) rather than a collection of tables (ie. a user table, a password table, an access table...).
In Perl this would be something like DBIx::Class.
A wiki is a great approach.
For database specific or project specific snippets it's also very useful to have links to where a similar construct occurs in the code. We use trac's wiki which gives nice integration with out SVN for this.
Another approach you may want to look at is creating views in your database. 'select * from some_view' can hide quite a bit of SQL. You'll still want to use a wiki to document them, but if its a view you don't have to worry about people keeping outdated copies.