Most online competition organisers will notify the winners by means of email (WEM or Winning Email). It is vital that entrants check their e-mail address line of any entry - there are no friendly postmen on the net to re-direct badly addressed mail!
Make sure you check your junk mail folders too. It has been known for winning emails to end up in the trash basket due to spam filters.
In some cases you may not receive any notification! Keep an eye out for the postman each day for those LWE's (Long White Envelopes) or BBB's (Big Brown Boxes). Your prize may not contain indication of where you won the competition, the reason for this is that many competition prizes are sourced from agencies and they send out prizes on behalf of the promoters.
Some competitions and draws post the winners name on the site, and ask that the winner CLAIM their prize. Thanks to the input of Loquax users you can also check someWinner's Lists that have been published on the internet. These are listed in our forums.
Be careful, not all winning notifications are valid. If you are asked to pay for a prize the it's likely you have not won anything. See our scams section for more details.