There are websites dedicated to advertising an abundance of giveaways on a daily basis. I use Canadian based websites which advertise giveaways available to Canadians. (Usually excludes Quebec)
Whole Mom was the first website that I had come across and have remained a frequent visitor. They advertise 5-10 new giveaways everyday, which include everything from Trips, to vehicles, to cookware and appliances. This websites doesn't host the giveaways but they includes links to the webpages that do.
Women's Freebies is a website I discovered recently. They advertise small and large giveaways from a variety of sources much like Whole Mom, though they do not often advertise the same giveaways.
Free advertises much larger giveaways from big companies, they also advertise free samples and coupons. It's frequently updated, but not on a daily basis.
Once you've clicked the link and have been brought to the page hosting the giveaway there's usually a simple form that you would need to fill out in order to be entered. You would provide your name, email, address, and age (There are some age restrictions). Some giveaway hosts use a form called Rafflecopter, where you would have to sign up with Rafflecopter to enter these giveaways. Now, I use one email address for everything and that's a personal choice. Though it would be wise to make a separate email address for giveaways only because those emails pile up. I have to delete between 80-120 emails a day, because they also send promotional offers and deals. I usually don't open them up unless it includes my winning prize.
3. Be Consistent
it's all about increasing your chances and being consistent. It's unlikely that your going to win by entering only one giveaway, so why not enter them all! This takes a lot of time and patience because this means entering at least 10 giveaways everyday. Some giveaways give you the option to enter multiple times a day or one time everyday and some giveaways give you the option to increase your chances of winning by sharing the giveaway on social media.