Professional development opportunities are tricky to find and tricky to attend. It often requires you to be out of the classroom away from your students. It's a bit funny how it works, you typically leave the school and your students for a day to learn how to better do something with your school and your students. You would think that it would work better if you were in your classroom with your students and the PD came to you.
Well, it can, with some creativity. I have found some great PD opportunities online and have been able to squeeze them in, without leaving my classroom, or ditch my students, and haven't had to spend a ton of money. Here's the magical acronym MOOC. I imagine that is not a new term for anyone, regardless, a MOOC or massive open online course is an opportunity to participate in a PD or furthering education courses related to your profession. There are a ton of free MOOC's and a ton of organizations that offer great courses. Here is a short list of a few places for some great Education MOOC's that can be used for PD.
Coursera
Coursera is a place to access free online courses offered by known colleges. Some topics many not specifically be geared toward teachers, but I bet you could find something useful. I have singed up for courses only to be able to access more materials that I might be able to use with my students.Udemy
Udemy is another place to access free online courses in various topics. Again, they are not specifically only education related courses. However, many of the courses are free, provide great resources and can be used for professional development or just for your own enrichment.
PBS Teacherline
PBS Teacherline is geared directly for educators. There are a variety of courses, some which are free, some are paid, and some are available for course credit.
ScholasticU
ScholasticU is a cool resource for teachers, however, it is pricey for an individual. I don't know about you, but my classroom budget is fairly small. Enough to obtain the necessities. This tool is really geared towards use within multiple schools in the district. If you look at the pricing chart, you'll notice that the price breakout is per school. You would be better off approaching your administration of superintendent and presenting the benefits of online options to them. School administrators want us in our classrooms working with students and they want us to continue to learn how to be better teachers, it should be an easy persuasive conversation to set up an account, hopefully. Regardless, there are great opportunities through this resource.
ASCD
ASCD has a large selection of professional development for teachers and is very reasonable priced. They do not offer courses for graduate credit, this is strictly professional development opportunities. However, the topics they offer are intriguing and the course I attended offered great ideas and resources.
Teachers First
Teachers First is a great place to take a course without doing much at all. You essentially sign up for a course, kick back and watch. The courses gain you access to moderators discussing the topic at hand and share the information through live videos. It is just like being in one of those professional development opportunities that school administrators provide for you, except you don't have to leave your classroom and can fit it in when it is convenient for you.
There are other sites and resources out there, but these sites listed here are places that I have used and have liked using for professional development. In my opinion, online PD is a huge time saver and money saver. You will not need to leave school for the day and arrange a substitute, you won't have to pay for a course, pay to travel, pay for food and then hope that the course is worthwhile. If you are looking for taking courses for credit, I would look through the PBSteacherline resource. There are great courses for credit, and the prices are not too bad.