Emily Gover, MSIS, Librarian and Ed Tech Community Manager
There are many great resources and people to learn from online in regards to this question. Specifically with the tools you mentioned, here are some resources on using Trello in education, and some resources on Pinterest in the classroom.
Educators like Tom Mullaney, Alice Keeler, Sarah Thomas, and many others have valuable blog posts, videos, and presentations to help you learn new tools. I encourage you to join Twitter (if you haven't already!), and connect with others through hashtag chats like #edchat, #edtechchat, and others. It's an invaluable resource for connecting learning with other educators. Good luck!