@ib2 @T-3D I've been a domain investor for over 10 years and have been very successful at it. There's a lot more that goes into it then just registering a domain name and hoping it will sell. You can list your domains on Godaddy auction listings or on premium listings, I've had a lot of success with those. Some good resources are namebio.com, dnjournal.com, namepros.com and others.
However, I'd argue that most people in the business really struggle as they don't understand what makes a good domain name and what's a bad domain name. While I do not work in this field full-time, I can say that I can make a living of it, but it's probably because I don't ask for absurd prices (e.g. randomword247.com domain name for $8000 is just unrealistic and won't happen) and therefore can sell domains easier. 
I have a question regarding a certain keyword though generic but it is trademarked and the trademark owner asked me to remove the parking page, is there a way i can offer my domain name to the company? What is the best approach in selling the domain to him without hard selling it and giving a reasonable price. I will be giving 10% commision to any domainer-mate that can help me pull the sale off.
For the following TLDs you can now find a expired/deleted domain list. .gi, .gl, .gy, .hn, .ht, .ky, .mu, .om, .pf, .qa, .rw, .sb, .sm, .sn, .st, .sx, .tc, .tl, .ug, .uy They also show up in the Deleted Domains (last 7 days) list and in the Domain Name Search, however they are not in the pending delete list! I do not have a working droplist for them yet, so that is why they are not released in the pending delete list yet.
Thanks for the great review on domain flipping. I could definitely see myself getting into domain flipping down the road. I constantly find myself thinking of domains that are probably worth buying. But the way you have presented and analyzed which keywords get the most page views makes it more like long term investing. I also never considered trying to market the domain names or that Adsense money could be generated. Thanks for sharing and good luck with your domains!
Sellers should also learn to identify premium domain names. Dictionary names are premium domain names. Domain names with dictionary-singular names are the hottest on the Web, and buyers are willing to pay a lot to purchase them. Names, such as search.com or askme.com, will get buyers more easily than long domain names. It is also important to note that unhyphenated domain names have more value. Even product-related domain names also can enable sellers to earn substantial profit. Once a seller has a certain degree of knowledge about the domain, he can start searching for buyers.
Length: This is pretty self-explanatory. Generally the shorter the domain name, the more valuable it is. This difference in value decreases exponentially as the name gets longer, though. For instance, the difference in price between 3 and 4 letter domains are significant, while the price difference between a 7 and 8 letter domain would usually be much less significant.