To what extent are the hadiths concerning the month of Muharram authentic, and is it permissible to act upon them?

The best fasting after Ramadan is during Allah's month of Muharram, which includes the fasts of Tasu'a and Ashura. There is no evidence to suggest that the first ten days of Muharram should be singled out for more worship than the rest of the month. In fact, no particular virtue has been established for it over the other sacred months.