In Hennepin and Ramsey Counties the board of trustees shall appoint a librarian and necessary assistants and clerical help, and fix their compensation. In all other counties, where a librarian is not employed by the county, the board of trustees may appoint a librarian and necessary assistants and clerical help and, with the approval of the county board, fix their compensation. In all counties where services cannot be provided by the Minnesota State Law Library, the board of trustees may contract with regional library systems for services.