Many local colleges and universities offer classes on design. In addition, there are many good books available at your local library explaining modern design as well as internent content.
There are several websites that can give you information on interior design jobs. One of the best sites with a lot of great information is "Careers in Interior Design".
You can find DIY information for interior design at a library, or you can find information from people at a hardware store. You can also ask your friends for information.
One can find more information on interior decorating on sites like decorating, decorating for life, all about design and many more. One will easily find information on interior decorating on these sites.
There are several websites that are devoted into interior design. One place that has specifically what you are looking for is at http://williamwilsoncorcoran.com/alumni/jobs/interior-design-sales-entry-level/
There are a variety of interior design websites with free information. Visit the websites GetDecorating, StyleAtHome, or DecorationIdeas. The HGTV website is also an excellent resource for design information.
You can find information on decorating advice from any online school for interior design or any interior decorator. Interiordecorators.com has a lot of good blogs and information for beginners and tons of great information!
There are many interior design programs, such as the Academy of Art programs that are online. However most design programs set for interior design is better to learn in person rather than just online.
There are a plethora of online schools that offer courses in interior design. Sheffield School has a particularly comprehensive course and that information can be found directly on their website.
You can find more information about interior designing courses from universities and colleges that offer such programs, as well as online platforms like Coursera or Udemy. Additionally, you can check out professional organizations like the American Society of Interior Designers (ASID) for resources and guidance on pursuing a career in interior design.
There are several good sites to go to when inquiring about interior design. I have found one called www.theinteriordesigninstitute.com. They offer classes on interior design. Home Depot does not do a course on interior design specifically, but they do have classes on paint and how to match certain color together. They also have classes on how to design with paint.
One can get information on careers in interior design from the following sources: National Careers Service, Independent, Career Planning, Careers in Interior Design, Fab Job, The Art Career Project, to name a few.
You can try the DYI do it yourself network site. They offer tips for interior design along with other projects for home owners. Also HGTV website is great for tips on design.