I think the moon can have some effect but it is relatively minor and should not be the primary factor that guides your decisions in the garden. Like I said earlier, don't do something stupid because the moon cycle says so, I've seen people really screw up their plants like that.
Like for example I know someone who was really into the whole lunar cycle thing and insisted that their plants go in the ground on a very specific date. It HAD to be that date no matter what. A few years ago a huge storm was predicted that week, but they planted anyway, because that was when the lunar cycle matched up. Well, their plants got the shit kicked out of them by a bunch of hail and rain and wind and it stunted the garden for weeks costing them a lot of yield and the end of the season. So be sure you are paying attention tot he other big factors, like the weather.
The biggest factor the moon has on harvest time for outdoor from what I've seen is you are a lot more likely to be ripped off on a full moon. In fact some people even refer to that first full moon in late Sept as a 'rippers moon' around here...