Tests
To determine if the mean or SD differs by group
Pooled t-test: if you can assume variances are equal and normally distributed
Separate variance  t-test: if you cannot assume variances are equal and normally distributed.

Wilcoxon rank sum test: numerical variables not normally distributed.
Paired t-test: paired differences normally distributed when studying central tendency(Two groups matched items or repeated measures)
Wilcoxon rank test: Paired differences not normally distributed (Two groups matched items or repeated measures)
F-Test: Numerical variables normally distributed (Two independent groups studying variability)
One way Analysis of variance: Numerical variables normally distributed (Three or more groups)
Kruskal-Wallis Rank Test: Numerical variables not normally distributed(3 or more groups)