You can also use sp_spaceused with a table name as its parameter:
sp_spaceused titles
name rowtotal reserved data index_size unused ------ -------- --------- ------- ---------- ----- titles 18 48 KB 6 KB 4 KB 38 KB
The rowtotal column may be different than the results of running select count(*) on the table. This is because sp_spaceused computes the value with the built-in function rowcnt. That function uses values that are stored in the allocation pages. These values are not updated regularly, however, so they can be very different for tables with a lot of activity. update statistics, dbcc checktable, and dbcc checkdb update the rows-per-page estimate, so rowtotal will be most accurate after you have run one of these commands has been run.
You should run sp_spaceused regularly on syslogs, since the transaction log can grow rapidly if there are frequent database modifications. This is particularly a problem if the transaction log is not on a separate device—in which case, it competes with the rest of the database for space.