It all depends on what sort of service you are after offering.
If I had the time now to study, with the aim of making money. I would look into Silverlite, and Sharepoint.
I believe that Sharepoint is going to become much bigger than it is now, and it is still a little of a dark art, so wages are high.
You would also need a good knowlege of SQL, mainly MSSQL, and maybe Oracle.
With a good knowlege of Sharepoint, C#, ASP, and MSSQL, you should be able to get a job easily. Throw in HTML, AJAX, and a little JAVA, and you should get a good job. Add on some basic e-commerce, and decent database design, then you could start a company offering web development.
You do not need to know as much if you are targeting one specific client, but the skills above would make life much easier.
There are so many sites out there offering web development, unless you can offer something different, new, or a lot cheaper, you are going to find it very hard.
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