You can earn the most bitcoins by freelancing. In my opinion its easier to find jobs that way as you are in a nieche that you can manage for yourself.
You can earn bitcoins by doing the advertisement. It basicly come to a signature campaign on this forum, but not only that. You can participate in a lot of others affiliate programs.
If you want to have a fun while earning a bit, and you do not mind the low payment, you can play games like Satoshigalaxy.com - an awesome MMORPG, or a Bitfootball.net - a football manager.
See in the few lines you have given so many ways to earn bitcoins. You just have to make up your mind that you will learn about the bitcoins and its future. Once your mind is ready, you just have to search google and you will find enormousness bitcoins earning opportunity. You can start even with a low payout work but it will gradually increase with time.