maintenance courses
I took the 2-day Rotax 912 inspection course at Lockwood in Sebring, FL, while I was building my RV-12 and found it informative and useful. But it gives you official permission to work only on the engine. It covers 100-hr inspections and routine maintenance related to the 100-hr inspection, like changing oil, balancing carbs, and compression check. Additional coursework is required in order to do major maintenance.
I later also took the 2-day LSA inspection course taught by Rainbow Aviation, offered in the Orlando area immediately prior to Sun n Fun. This qualified me to apply to the FAA for a Repairman Certificate that allows me to do the annual condition inspection on the entire airplane, but only on my own airplane.
It seems illogical to me but anyone is allowed to do maintenance on an experimental airplane. However, signing off inspections requires appropriate certification.