Affiliate marketing will give the better opportunity to make the most money. AdSense will make you smaller amounts of cash regularly with very little maintenance. However, it needs a fair amount of traffic to be really profitable, while you can use a mailing list to sell your affiliate products. You can build up a large list over time, even with a small amount of daily traffic.
But the biggest factor that determines how much money you will make, is joining a training program that will help you success. It is very hard to expect success right away if you are a beginner and all alone. The best program that offers you the information, help, tools and support to succeed is Wealthy Affiliates. Some Wealthy Affiliate members are already making over $8000 a month after only 6 months of being a member.