SQL Server BOL is your friend.....
The TOP clause limits the number of rows returned in the result
set.
TOP n [PERCENT]
n specifies how many rows are returned. If PERCENT is not
specified, n is the number of rows to return. If PERCENT is
specified, n is the percentage of the result set rows to return:
TOP 120 /*Return the top 120 rows of the result set. */
TOP 15 PERCENT /* Return the top 15% of the result set. */.
If a SELECT statement that includes TOP also has an ORDER BY
clause, the rows to be returned are selected from the ordered
result set. The entire result set is built in the specified order
and the top n rows in the ordered result set are returned.
Phil