Two important questions to ask yourself about the job a major will get you:
1. What is the unemployment rate on these jobs?
2. Will this job be automated in 5-10 years?

Health
-Your health is very important for your success
-Getting enough sleep, having a good diet, maintaining energy levels, and being healthy will contribute to your long-term happiness and success.

Sleep
-Melatonin is a supplement that many rationalists take to get better sleep at night
-Sleep Cycle is a good app that monitors your REM sleep cycles and wakes you up in a 30 minute time period when you are closest to being awake
-Setting an alarm at 9:30pm to be able to keep track of time late at night can help avoid the "oh god, it's already 2am?" effect. It also helps avoid...
-Hyperbolic Discounting

Diet
-You will be determining your own diet for the first time in your life
-Most freshman gain lots of weight after starting University due to poor diet and not knowing how to feed themselves in a healthy sustainable way
-Your diet is important for maintaining your general energy level and keeping you healthy
-MyFitnessPal is your new bestfriend for keeping track of what is in the food you eat and for losing weight
-If you want to lose weight: Avoid getting calories from liquids
-Eat and drink far less sugar. Sugar turns in to fat and has tons of calories. Soda and sugary coffee drinks are your new worst enemy

-Edit-
People on Slack reccomended
Cal Newport
and in the same vein as Cal Newport: Why Generation Y Yuppies Are Unhappy