First thing you need to understand is what oxidation is. Tae a look at your skin during the cold dry months, and you notice a flaking, and/or dry appearance. this is identical to what your car surface goes through, however you
cars "skin" does not rejuvinate. So its up to you to protect it properly, from the get go.
Paint cleaners, in conjunction with a clay bar, are products designed to remove such naturally occuring defects in your paint. This would without a doubt, be your first step in rejuvination.
Step 2, or in leiu of step one, would be to use a polish, which contains abrasives, (very minute, and in different levels of abrasiveness) to abrade away the dead paint (skin cells). This can be done by hand or PC (Porter Cable Random Orbital Polisher) Better results are obviously obtained with this machine.
Step 3, would be to seal what you have just rejuvinated. A couple of options are available. Carnauba, which povides natural protection, for several weks, or a polymer, which will yield identical looks, but for about 3 times as long.....
By no means should you attempt using a "compound" or wet sanding techniques.....always start with the least aggressive method, and achieve results through levels of satisfaction.