Hi Nsane,
You can start a blog, but be careful in what niche you are going to start the blog. Choose your niche carefully, don't just go out and buy a domain name, do some keyword research first. I suggest you do the keyword research with Long Tail Pro, it's an amazing tool, better than Google's Keyword Planner.
You should make the blog in a niche that you enjoy writing about, a niche that you really enjoy. Add some quality content on your blog, make sure it is unique and keyword targeted, but in the mean time don't forget to write for the people not for the search engines, you could add 3-4 keywords in your article, maybe 1 keyword in the title of the article.
The platform to build your blog on should be Wordpress, it's not only me who recommends it, but there are a lot of people using it, even the big sites like mashable.com use Wordpress. Make sure you install a SEO plugin, Cache plugin, Social buttons and other plugins that you need. I'm also suggesting to start an email list, you will earn extra with the email list.
I would not add ads on the blog at the beginning, but in time when you will get more visitors to your blog then should be the right time to add some ads. Google AdSense are a good option, but you can always put CPA offers on your site. It just really depends on your niche.
About the traffic; you can have 10k UV / day and earn $10-20 / day. Or you can have 150 UV / day and earn $100. It all depends on the quality of the traffic that you have.
All the best,
Gabriel