Here are some resources that have been recommended to me as being good for beginners. I haven't tried these myself—feedback welcome!
It's always good to have a specific project in mind, especially once you get past the very introductory chapter. If you are new to programming, start small. Don't have a research question? Use something simple you can relate to. You can find a dataset online, or make up some of your own data:
- Plot the number of cups of coffee you drink per day for a week
- Plot coffee vs. water (two variables!)
- Athletic? Plot running times, workout frequencies, etc.
and so on. Be creative and try to find a project that you actually care about (even if it's silly).
- Antonia Hamilton's MATLAB for Psychologists (PDF)
- Coursera Learn MATLAB
- Introductory lectures from the MRC CBU
- MATLAB Academy from MathWorks (the makers of MATLAB)
- MIT open courseweare Introduction to MATLAB