I dont think that the Prov will hurt. If anything, you may find that it helps a little with estrogen and binding to SHBG, allowing a little more of your test to remain free. Overall though, it won't be a huge difference in your results if you use it or not. You can start it as early as the begining of the cycle. I would still use a small dose of Adex though, especially if you are sensitive to estrogen. You may find that you need a little more while using dbol than in the rest of the cycle. .5mg 2-3x wk should be enough. Some may need .5mg EOD. 

Just to clear one thing up, Nolvadex is not an AI but a SERM, selective estrogen receptor modulator. It will not reduce the amount of estrogen but will bind to specific estrogen receptors. As long as you control estrogen with your AI, you will not need it on cycle. The only time I would suggest it on cycle, for this cycle, would be if you ran into an issue with gyno. Other than that, save it for PCT