I reluctantly agree with your consultant. At most organizations, SQL Server is becoming too vital to the company to simply be ignored. And despite our best efforts, not all applications will get migrated to Oracle. Experienced Oracle DBAs can bring excellent professional practices to SQL Server, but in my experience it takes more than a book, although you can find books and other resources with a simple Google search. Even Microsoft offers a three-day workshop, although that is oriented more toward migrating applications from Oracle to SQL Server. Look for a local class that caters to experienced Oracle DBAs. Have one of your staff take the class, then provide recommended changes to tailor the class to your staff, then have it taught on-site. Create a plan for everyone to perform some regular tasks on SQL Server so the training isn't wasted.