1) The Coaching Manual
One of the finest resources I've come across is tailor made for coaches and focuses on grassroots coaching upwards. The Coaching Manual describes itself as a "unique online resource for soccer coaches and teachers" and contains behind the scenes footage of Academy coaches sessions. One of the best parts of the site is not only the sessions available but the ability to watch how other coaches communicate, deliver sessions and flow from one progression to the next.
Check out the Coaching Manual here.
2) Watch/Shadow Other Coaches
Whilst Youtube is a great resource for finding sessions and watching different activities, there is no substitute for actually being there. Watching other coaches in action allows you to pick up different nuances in how they coach, perhaps gain a different perspective on how they interact with players and allows you to catch all the stuff that maybe eludes the camera if you're watching it back online.
The biggest bonus is the ability to ask questions and get insight from the coach on why they did something a certain way. This is something you can't get from watching videos online. As with a coaching course, take what you like from the session and leave what you don't. Your mindset should be 'how can I adapt this to help improve my players' rather than 'this is a good session I'm going to perform it verbatim'.
Discussion and asking questions are crucial to coaching and develops a growth mindset. This is especially true if you're looking to learn and gain insight into the Who, What, Where, When, Why of a session (read my piece on the W questions here). Twitter is a fantastic resource for coaches looking to connect, discuss and debate the beautiful game. There is a wealth of knowledge and content and you can tailor it to your own tastes and philosophy. Just make sure you choose your follows and unfollows wisely.
As an added bonus, you can favourite, retweet and share your own content - allowing you to build up a resource of coaching material that you can go back and find later. (Note to self, coaches prefer their tweets being retweeted rather than favourited).
Podcasts are a resource that I've only recently found myself exploring and I can't tell you how good I think they are. There are a number of people out there creating fantastic content about any number of subjects and I'm pleased to say that there are quite a few dedicated to coaching.
The Coaching Manual has it's own podcast and the content is excellent. I recommend #06 Hunter Maats and Katie O'Brien which is focused on how children learn and #12 Edu Rubio who has some great insight into the motivation of youth players and how coaches can learn and develop.
You can find the Coaching Manual podcasts here.
Pro Tip: Download the Overcast App for iOS and queue up your podcasts for listening to on your phone or in the car. Find the Overcast App here.
Get out there and coach. By far and away the best resource you have as a coach is your players. Get out on the field and deliver sessions. It doesn't matter what level you're at, practicing your trade and coaching is the biggest thing you can do in order to improve as a coach. Deliver sessions in different ways, try different activities, use new examples and figure out what works and what doesn't for individual players and groups as a whole.
Learn by doing. Plan your session, coach the players, reflect on how it went, revise the content for next time. Repeat. Plan, coach, reflect, revise.
We expect players to take charge of their development by practicing in their own time. Using the tools and resources above, coaches should be able to do the same.