The American Library Association (ALA) offers professional development courses that run through all types of librarianship. The main ALA eLearning page lists the continuing education options offered by the different subsidiaries of the association.
The American Library Association is dedicated to libraries of all types across the country to help them with whatever their needs may be. This includes providing professional development on the different topics and fields of librarianship.
You can access ALA eLearning here: http://www.ala.org/educationcareers/elearning
This site has a combination of courses and webinars available and the topics depend on the section of ALA that the user is consulting. Some of these resources are free and others have a fee. The fee range can start at $50 and go up to at least $200, but it depends entirely on the course.
American Association of School Librarians (AASL) is a division of the American Library Association. AASL specifically caters to school libraries, and creates publications such as the National School Library Standards.
AASL eLearning can be accessed here: https://www.ala.org/aasl/learning. Conference information can be found at https://www.ala.org/aasl/conferences. Standards, including crosswalks, are here: https://standards.aasl.org/.
Many of these resources and programs are funded under the provisions of the Library Services and Technology Act from the Institute of Museum and Library Services.