Yes and no. For parking or developing they could work well.
But you will only make money on parking a new domain if the domain is something that people type in directly to see if there is a site there, like say "cadfood.com". If people don't type it in, how are you going to get any traffic? The number of searches each month means little if people cannot find it.
You can optimize and promote your parked domain, but most domain parking services don't allow this, so check with them first or they may close your account.
Noomle.com is one place you can "park" your domain, add content, and promote it like any other. They use Adsense to display ads. This is easy, but your choices for what your site looks like is limited. This is better for people that have many domains and no time to spare.
Development is almost always good, but it helps to know a little about building a site and web marketing concepts such as link building and SEO.
But if you are going to do develpment, you need to know that while a keyword-rich domain can help a site, the amount that it helps is quite small when compared with what you can do with a truly BAD domain and a lot of content and SEO. Our Bizprolink-Internet.com is a good example of an awful domain name on a site that does really well (80k uniques a month) anyway.
Ask lots of questions and read as much as you can and you will avoid some of the mistakes that I and others made when we started. But listen to many different people because some of us don't know what we are talking about. Someone may say "This domain has a top ranking for the keyword phrase, so you have to have that." but they ignore the fact that the site has that keyword all over the place and in links pointing to the site.
