You'll find a large and growing demand for programmers knowledgeable in VB.NET and C#. The demand for AcuCOBOL programmers is not very large and there is a large body of experienced COBOL programmers vying for those few jobs. Me? I'd opt for the C# work if I could get it.
As for tutorials, there is nothing specific to AcuCOBOL that I'm aware of. There are some white papers and technical tips on the AcuCorp web site, but . . . If you're not alread a COBOL programmer, there are a number of forums like this one for questions. All in all, you'd be best off buying a general COBOL book that includes one of the free PC compilers.
3gm