I have mapped a few reads to several reference genomes and have measured gene expression (expression level of a bunch of genes in these genomes). The expression level I measured is simply coverage/length of gene. I need to analyze the data, I was looking for some insights on which tests to do, or which plots to draw to get a sense of how to interpret these results. For example somewhere I read log transformation of expression levels is a better measure. Is there any test I can do? T-test or something like that. I'm a newbie and have no idea what to use.