Pre-Linear Regression Tests

Before doing a linear regression on a data-set one needs to find out a few things about the data:

• is there is a linear relation between the dependent and independent variables
• are the variables normally distributed (if not, do a Data Transformation)

Questions:

1. Book1.xlsx
2. In Excel, do I simply use the CORREL() function to determine a linear relation between the dependent and independent variables?
3. How do I interpret these results (i.e. low value = low correlation, high value = high correlation)?
4. To test normality, can I simply use the QQ Plot test or should I use other tests, like the K-S Test as well?
5. How do I interpret the K-S Test results?
6. How do I go about doing a "Data Transformation" and how do I know whether I should do it?
7. Please do not confuse things with only Statistics talk when giving an answer because I might not understand what you're saying. I've uploaded a sample of a data-set.

Thank you!