A/B testing and Multivariate Testing(MVT) are popular testing methods used in web analytics. Can anyone tell me which statistical procedures I should use for these testings?
Any of the linear model procs should give you what you need. See the documentation for PROC GLM, PROC MIXED, PROC GENMOD and PROC GLIMMIX (most likely the latter two since I think your data will probably have a non-normal distribution).
ANOVA, or Analysis Of Variance, is used to compare the averages or means of two or more populations to better understand how they differ. Watch this tutorial for more.