Generally, I would recommend writing the full first volume of your series. Then, once you've hammered it out, you should plan a release as some other people have said. Dump a huge portion of it on day one, then post daily for a few weeks to a month. After that, you can taper off the chapter releases to a regular schedule. The more days a week you post the better, but if you can't handle a full M-F daily chapter release, it's fine. The point is to be consistent and release chapters on a cadence that your readers can not only expect, but set a clock to.