Developing a website doesn't really increase the value of a domain. It lends value but that's the value of everything external to the domain name itself, especially those externalities that have some degree of permanence.
You want hints on SEO, keywords, directories? Read WebmasterWorld. Extensively.
There's no fast and easy way to online success, unless it's the fast and easy way that marketers of "success" products/courses make their money - peddling Webdev basics to the uninformed, the lazy, the greedy - and taking the fool's money in the process.
some people (not experienced) are impressed by the whole fact.
I had a client ask whether I paid Google to show up on the list! ;)
p.s.> I created a website for this client and wasnt selling a domain so its a bit different