You want to malt your own barley you mean? I don't really know much about doing that.
The temperature for the mash varies based upon what kind of beer you're going for. In general, the higher mash temperature will create a more full-bodied beer. If you just want to shoot for average then 153-155 degrees F (67-68 Celsius) is a good temperature. Mash it for an hour, and keep it in primary for about three weeks.