Why is Safari taking several minutes to open?

Go step by step by step and test.

1. Power off the router. Unplug it from the wall. Wait a while.

Plug it back to the wall. Power the router on. Wait until all the lights are lit properly. It will take a while.

Restart the computer.

Start up in Safe Mode.

http://support.apple.com/kb/PH14204

2. Delete Caches.db

Close all windows and quit all applications.

Hold "option" key down and click "Go" menu in the Finder menu bar.

Select "Library" from the dropdown.

Library > Caches > com.apple.Safari > Caches.db

Right click the Caches.db file and select "Move To Trash.

Close windows and relaunch Safari.

3. Empty Caches

Safari > Preference > Advanced

Checkmark the box for "Show Develop menu in menu bar".

Develop menu will appear in the Safari menu bar.

Click Develop and select "Empty Caches" from the dropdown.

Only Safari? Not any other application?