I've seen ways to collect soil samples, but I would like to know if there are standard procedures for collecting soil samples for microbiological study.
There is no standard procedure that fit weel to all soil samples or all microbiology study. A common place is to put in plastic bag and cool over ice until lab manipulation.
As already Jose stated, no standard method exists and it greatly varies with the type and nature of microorganisms that you expect to isolate. However, a common procedure is to store them in airtight containers or plastic bag at 4°C under darkness and culture them as soon as possible.