The sys.tables and sys.columns objects will return this information for you. The following SQL statement will bring bring back all the colunns in all the tables ordered by the table name then the column name.
SELECT
tbl.name AS table_name,
SCHEMA_NAME
(schema_id) AS schema_name,
col
.name AS column_name
FROM
sys.tables AS tbl
INNER
JOIN sys.columns col ON tbl.OBJECT_ID = col.OBJECT_ID
ORDER
BY schema_name, table_name;