I'm a self-proclaimed "serial entrepreneur", which drives my wife nuts. Not only do we have multiple real estate investments, we also opened a wine/liquor store and recently launched an online website & podcast called Serial Startups (SerialStartups.co). The website is aimed at filling a unfilled niche in the market, which is how to manage multiple businesses and maintain your relationship with your spouse and family. We share a lot of great content and advice on the blog, so check it out!
We also recently launched our personal site with lots more content around entrepreneurship and how to build your desired lifestyle through business. Check it out @ tomandariana.com
I began learning about real estate in the summer of '07 and purchased my first duplex that December. Since then my niche is buy and hold properties (thus far a mix of SFH, duplexes and 4-plexes, but shifting into more commercial properties).