Thing to Do Now (in Priority)
If you:

don't have a virus now

think that you have a virus or spyware infection now then:

Buy or download an Anti-Virus program and Update constantly

see link for suggestions

Disconnect yourself from you network immediately. This will stop a potential spread to others on you network and also stop a mass email bug from spreading its SPAM to others.

Install Spybot Search and Destroy or Adaware and run Update and Immunize

Feel free to make a donation as well. Making this software is an endless task.

Restart your computer from an Anti-Virus CD (Best to buy one like Symantec or McAfee

Install Zone Alarm Firewall (not Pro version).

Doing this will require some learning so the software can know what's is ok to pass through the firewall and what is suspicious.

Don't know what a Firewall is?

Check your Task Manager or Task List (see link on Using Task Manager)
This will tell you if perhaps there are odd things running under the hood. But not all viruses will be noticable in Task Manager.

 

Check on Google about these thing that you may find suspicious
  Research Removal methods and double check your sources (then see the prevention actions on the left)

See My Resources Page and check link on the rest of the main page
for more detailed descriptions and info