Anyone can help improve this list of resources, to do so make sure your pull request meets the following guidelines:

Make an individual pull request for each tip.
Only submit resources that are completely free to access.
The pull request and confirmation should have a helpful title.
Use upper and lower case (AP style).
Use the following format: [Useful title] (link)
Link additions should be added to the end of the relevant category.
New categories or improvements to the existing categorization are accepted.
Please check your spelling and grammar.

¡Thanks for your support!