Firstly.....
Setting up your p.c so you don't get hacked and learning a few basic disciplines that all stoner's should practice online , basically your Primary email ( the one your isp gives you - joebloe@bigpond.net ) is your first weakness and needs to be protected.

Email Security Discipline
1. Do not use your Primary email address for anything online , do not use it as an address for your Yahoo or Flickr account etc. Only use it for work , family and real life friends  and encourage your friends not to forward your address in group emails.
2. Only open emails from those people that you know and are in your address book. Read the Subject line of the mail carefully and only use the preview window at the bottom in Outlook Express - DO NOT OPEN ATTACHMENTS FROM PEOPLE YOU DON'T KNOW ! 
3. For all your online memberships to various groups , sites etc use a Hotmail or Gmail or similar , these mail programs come with inbuilt updated virus and spam filters ( so the bad stuff is opened on a website not on your p.c ) and because they are online you don't lose shit if your ISP goes bust or you don't pay ya bill ! 
4. For these accounts use a fake name , no one gives a shit , it's not illegal.

Computer Security Discipline
1. Do not use your name in the box where you describe the computers owner ( Control Panel / System / Computer Name ) as this can be imprinted onto cookies , also just call your Work Group and Name something boring like HOME and WORK so it doesn't stick out IF you get hacked.
2. Use the log on password entry for XP because if your p.c gets nicked at least the junkie fucks can't use it and your missus can't find yer porn as well !
3. Go to Control Panel / Security Center and turn the Windows Firewall on and enable updates , this is the only firewall you will need it runs quietly in the background and updates itself , you could get programs like Norton , M'Caffee etc but they will expire , lag your p.c , and need updating to be any good , also they will annoy the shit out of you with false attack reports and make you more paranoid than you already are - as it says DISCIPLINE ... do this shit I say and you will be fine

Website Security Discipline
1. Do not visit porn , crack / serial / warez / hacking sites - period ! *
2. Do not download programs from these sites ( * ok I have done this and 50% of the time I've got what I've wanted , the other 49% I got some dodgy spam prog and the 1% I got a fucken virus ....  remember 100%  DISCIPLINE.... )
3. If you have been surfing dodgy websites then clean your cookies and temporary internet files  regularly ( Control Panel / Internet Options ) also consider getting a program like Adaware to remove any picked up spyware.
4. Do not use your real name to join websites or your primary email unless it's something like Ebay or Paypal where you need to make money transactions etc.
5. Don't post picks of yourself holding pot , bongs etc and don't post pics of your crop online in sites like Webshots , Flickr , Yahoo etc - once it's online it can be copied many times and worse .........

Chatroom / Messenger Security Discipline
1. Only add people you know and have talked to to your buddy list
2. Do not accept any file transfers ( pics , programs ) from people you don't know very very well.
3. Do not click on any links displayed in a chatroom or personal message from people you don't know well.
4. Only use your real picture on your profile if you feel comfortable with it - remember it can be copied  , try to avoid pics with your car number plates , work place , home interior showing ,  do not use your real name in your details and do not display your kids and pets names ( see below )
5. Don't use your own name or kids / pets / wifes name as a password , also don't use the year your were born or wife , kid's etc - hackers can get this info easily and use it to gain access to various accounts. Use your imagination and use a combination of caps , numbers and lower case ( i.e 33REd77 )
6. Do not use add - on programs that add different features to your messenger and avoid booters , bots etc at all cost's.