Read this SQL tutorial to learn when to use SELECT, JOIN, subselects and UNION to access multiple tables with a single statement.

Modifies a column's values in existing rows of a table or view. Restriction: You cannot use UPDATE on a table accessed via an engine that does not support UPDATE processing. You can update one or more ...

I know in Oracle you can use DBA_TAB_COLUMNS (or ALL_TAB_COLUMNS). My SQL Server knowledge is very rusty, but can't you use the INFORMATION_SCHEMA.COLUMNS view?

Adds columns to, drops columns from, and changes column attributes in an existing table. Adds, modifies, and drops integrity constraints from an existing table. Restriction: You cannot use any type of ...