Like all starting out, i've thoroughly confused myself with how to start out.
I'm a web designer, and use intensive website scripts for my clients - scripts such as joomla, wordpress, phpbb, magento, etc.
Some of these don't always play well in a shared environment. Most of the time they are fine, but occasionally can lag.
I have enough clients to justify starting web hosting - but I don't want the business to just support my web design clients - I want it to be viable as it's own company. Being a webmaster, I have a good "tech" thumb. However, I am not comfortable in administering in root linux.
So - in choosing how to start this business I have 3 choices which all have their pros & cons and I'm in a mental quagmire deciding.
I can go reseller - I've been thinking about eleven2, hostnine, or westnic for this.
I can go managed vps - I have a vps with knownhost, but also thinking about hostv (due to backups & management) or with directspace.net (huge bandwidth).
or I can go with a managed dedi - I would probably choose directspace for this as well (managed dedi with 10tb of bandwidth)
So I'm stuck. Do I go ahead and front the money for the dedi but lay off of some of my advertising budget - or do I start reseller, and have more money for advertising but my clients would be in a shared environment (probably larger & possible more oversold than if I had my own dedi).
I haven't heard any real bad reviews about any of my potentials mentioned above.
I'd go for a dedicated server based on your disk space and data transfer requirements and the fact that your web design clients will likely appreciate the fact that you/they have a box to yourself/themselves.
Check with your provider and see how much they'll support you in managing your own web hosting business. I probably wouldn't recommend starting a stand-alone web hosting company while being uncomfortable administering servers.