Someone is sending me crap

Is there anyway to find an IP address from someone that is sending me viruses via anonmail or a program like that?? if so how do i do this and what programs will i need...?

No.

With some anonimous email providers you can contact the providers and tell them about the abuse of their system but they won't provide you any information. Even if you take the whole case to the highest court, they still might continue to refuse to provide you that information, unless you're a Law officer doing some investigation to some very serious, criminal offense. Even then, you will need a court order to force those providers to turn over the information.
So actually the proper answer is 'maybe' but the costs and efford required to find out this information is often not worth the trouble it caused.

There is one simple trick that might work but you'll need your own webserver for that. You just respond to the email with an HTML-formatted email and add a webbug to the email. (An image of 1x1 pixels that is located on your webserver.) When the recipient reads the email, chances are that he will see it as HTML and thus he will access this webbug on your system. Thus his IP address gets logged by your webserver.
But if this is a spammer, you'd only be confirming the existance of your email address this way. Even worse, he might not even bother to check those response emails. Or his mailreader just displays them as plain text and blocks those webbugs.

So, personally I stick to 'No' as answer.

It might not be deliberate. Some viruses will just mail out to every address in an infected address book. They'll usually change the address that is appears to come from to cover its tracks.

i.e. you get a virus mail appearing to come from JBloggs@hotmail.com but it could have come from GWB@thewhitehouse.gov.

If you think someone is sending these deliberatly there really isn't much you can do except change your email address or make sure you have [up to date] antivirus which will scan your incoming mail.

If you are running email software you could write rules which only allow mail from an approved whitelist to get into your inbox. You'd need to edit the rules everytime you need to add a new 'approved' sender.

Changing your email is probably the easiest.