Is a single male permitted to light the shabbat candles and say the blessing? And if so, how many candles? Do the rules change based on whether alone or in the company any single females?
Men and women are both obligated in the Mitzva of Shabbat candles and saying the blessing. Women have precedence to ensure the Mitzva is fulfilled because they are more often at home preparing the house on Friday afternoon. (Shulchan Aruch OC 263:2-5 and Mishne Torah, Hilchos shabas ch. 5)