So I figured it's high time to break down what all those sources actually mean . Now, depending on what software you're using to measure all of these things, they may be bucketed slightly differently, but these definitions are pretty common across most tools you'll encounter. Make sure to double check on the finer points of some of them, but this should be a good starting point for you if you're new to this whole marketing measurement and analysis "thing."
Would you mind sharing your stumbleupon user name with me? I would love to follow you and your shares! :) I am beginning to get more active on SU and it is definitely paying off. I have had a few posts in the last several weeks that have brought in 600-700 visits each. :) In regards to your "challenge" I am going to try out I will let you know how it goes.

You had to know social media would be on the list. I generally recommend that a site only have a presence on 2-3 social networks, at least while they’re small. It’s a lot of work to maintain, engage, and update a social network profile, and keep its messaging consistent with your branding. You can always spay someone to do it for you, but then it’s not a free traffic source, is it?
A link in the comment itself may or may not be called for. I recommend only including a link of you have a post on your site that ties in nicely. If you do, you can use it to expand your comment. “By the way, I wrote a post on this topic as well over here. My conclusions were X and they seem to contradict yours; what are your thoughts?” If you aren’t able to work in a relevant post, limit your link to in your profile for the comment, where the website field sits.
Direct traffic is people who type your URL into their navigation bar, or who use a bookmark. These are your regular visitors, people who’ve discovered you in some other way and are now coming back, and — less now than in the past — people who type in a URL they’ve seen on your offline ads or who guess your web address based on your company name. Direct traffic is often the highest converting kind, but it can also be regular blog readers or your own staff. Filter your workers out if at all possible to keep your data clean. If you can’t filter them, at least ask them to use direct methods (rather than search, for example) and you may be able to identify it when you work in Analytics. Any traffic that Google can’t identify will also show up in Direct traffic, and that can include ads if you haven’t hooked up your ad accounts with your analytics, email or SMS campaigns if you haven’t tagged them for Google, and other sources that aren’t identified. Tag well and you’ll see less of this.
We used to like best to see a fairly balanced mix, back when there were mostly just three sources: Organic, Direct, and Referral. Organic Search traffic is a good sign of general site health, it’s usually the top source of conversions, and it generally shows great ROI. Direct traffic is often the people who love your site or are coming back to buy after they found you in some other way. These two groups of visitors are probably the ones that bring you the most sales or leads.
Organic traffic is the primary channel that inbound marketing strives to increase. This traffic is defined as visitors coming from a search engine, such as Google or Bing. This does not include paid search ads, but that doesn’t mean that organic traffic isn’t impacted by paid search or display advertising, either positively or negatively. In general, people trust search engines, and sayings such as “just Google it” reinforce that humans are tied to the search engine. Thus, paid search, display, or even offline campaigns can drive searches, which may increase organic traffic while those campaigns are running.