By installing HD Tune 2.55 - Hard Disk Utility, you can easily monitor your hard disk. HD Tune 2.55 - Hard Disk Utility has 4 menus, such as Benchmark, Info, Health and Error Scan.
From Benchmark menu, you can see the graph of Transfer Rate Minimum, Transfer Rate Maximum, Transfer Rate Average, Access Time, Burst Rate and CPU Usage.

From Info menu, you can find the information about Firmware version, Serial number, Capacity, Buffer, STandard, Supported, Active. From this menu you also can manage the supported features, such as: S.M.A.R.T; 48-bit Address; Read Look-Ahead; Write Cache; Host Protected Area; Device Configuration Overlay; Firmware Upgradable; Automatic Acoustic Management; Power Management; Advanced Power Management; Interface Power Management; Power-up in Standby; Security Mode and Native Command Queuing (NCQ).

From Health menu, you can find the information about Raw Read Error Rate; Spin Up Time; Start/Stop Count; Reallocated Sector Count; Seek Error Rate; Power On Hours Count; Spin Retry Count; Calibration Retry Count; Power Cycle Count; Power Off Retract Count; Load Cycle Count; Temperature; Reallocated Event Count; Current Pending Sector; Offline Uncorrectable; Ultra DMA CRC Error Count; and Write Error Rate.

From Error menu, you can find the information about percentage of damaged block, scanning speed, position and elapsed time.

You can download HD Tune 2.55 - Hard Disk Utility from: http://download.cnet.com/HD-Tune/3000-18512_4-10974407.html