"I currently run 10 sites, with #11 in the building process and not indexed yet. I've paid a few writers to write quality articles built around relevant keywords to populate the pages for each site, and I have written many more myself. It's a lot of work, but honestly, it's also a learning process. I feel like I've gone to school on many of the site topics. That's what I was getting at before: don't be afraid to get in there and research a topic, then build a site about it. Time consuming? Sure, but it doesn't have to be that big of a deal. Learn as you go. I'll focus all my time on a new site for a couple of weeks, doing basically nothing else. When I have the skeleton of that site set up, it's just a matter of filling in pages, which I do a bit at a time over a couple of months, as I'm working on my other sites as well.
Remember: most of the people looking for what your site is about are not experts either. I can't tell you how often I get emails from different people thanking me for giving them very basic (but to them, important) information on one of my sites. I think too many webmasters get caught up in thinking their site has to be the end-all be-all, the final word on this or that topic. C'mon, it's a big web, right? Don't try to be everything to everyone, unless that's what you want (and there's nothing wrong with that). Just don't think that you have to be some kind of expert on a topic to build a site about it. I think THAT is what scares too many people off and prevents them from expanding their businesses into other topics.
How did experts attain that status? Someone taught them. When you do research on a site topic, you're learning from someone else. Same thing as the experts - only you're not devoting so much time to get to the expert level. You're just packaging what you've learned and (hopefully) imparting it to others who find your site from a search engine. I remember the first site I built about something I didn't know a thing about beforehand. I was afraid it would be too simple - that people finding the site would not gain anything from it. I was wrong. Trust me, even if you do a little bit of research on the topic, what you then impart will be of major help to someone who knows nothing about it. I know because I got lots of comments about that first "know nothing" site, and most of them were 'thank you' emails from someone who took away something useful from my site. That's very gratifying, and from then on I was unafraid to build sites on topics I knew little or nothing about. Just do it!
Finally, I'll say that I think I'm reaching my limits for a one-man operation. I think about 10-12 sites will be my personal limit. At that point, I'll invest more of the profits into hiring writers and maybe a webmaster to handle the time consuming aspects of running it all. Having said that, I'm sure many others can handle twice as many sites, and some probably can't handle half as many. That's another part of the learning process - you learn your limits. Just don't let the fact that you know little or nothing about something stop you. I feel certain that it does stop too many folks who don't give themselves nearly enough credit." Swebbie