Safari 5.1.7 is behaving badly. It's sloooooow. Why?

Question

Safari is going so slowly I'm about to scream.  The ball just rolls and rolls and rolls when loading or reloading a page.
What are the possible reasons and how do I fix this.  It's driving me crazy!  Thanks.

Answer 1

Thank you for the reply... but I'm thinking that since this is something I absolutely do not know how to do, I might mess it up and then what would I do to get it back?
I know nothing about DNS other than what it means.
The instruction from Apple is seriously lacking and google says: 
Note: We recommend that only users who are proficient with configuring operating system settings make these changes.
The instructions are:
Example: Changing DNS server settings on Mac OS 10.5
From the Apple menu, click System Preferences, then click Network.
If the lock icon in the lower left-hand corner of the window is locked, click the icon to make changes, and when prompted to authenticate, enter your password.
Select the connection for which you want to configure Google Public DNS. For example:
To change the settings for an Ethernet connection, select Built-In Ethernet, and click Advanced.
To change the settings for a wireless connection, select Airport, and click Advanced.
Select the DNS tab.
Click + to replace any listed addresses with, or add, the Google IP addresses at the top of the list:
For IPv4: 8.8.8.8 and/or 8.8.4.4.
For IPv6: 2001:4860:4860::8888 and/or 2001:4860:4860::8844
Click Apply and OK.
Test that your setup is working correctly; see Testing your new settings below.
Repeat the procedure for additional network connections you want to change.
I have no clue which setting needs changing or what IPv4 or IPvv6 mean or why why one should be chosen over another.  This looks an easy way to really screw things up since I have no knowledge about this sort of thing.
Is this the only way to fix the problem?
Thanks.