Here's a basic rundown:
А/a = a (as in "father")
Б/б = b (as in "bat")
В = v (as in "vine")
Г = g (as in "grape")
Д = d (as in "don't")
Е/е = ye (as in "yes")
Ё/ё = yo (as in "yogurt")
Ж = s (as in "pleasure")
З = z (as in "zap")
И = e (as in "me")
Й = y (as in "toy")
К = k (as in "kill")
Л = l (as in "lamp")
М = m (as in "map")
Н = n (as in "nope")
О = o (as in "more")
П = p (as in "pat")
Р/р = r (rolled)
С = s (as in "see")
Т = t (as in "tool")
У = u (as in "boot")
Ф/ф = f (as in "face")
Х = x (makes "ch" sound as in "loch")
Ц = ts (as in "sits")
Ч = ch (as in "chip")
Ш - sh (as in "sharp")
Щ = sh (as in "sheer") OR sh-ch (as in "fresh-cheese")
Ъ = silent, no palatalization of preceding consonant
Ы = do not attempt
Ь = silent, palatalization of preceding consonant
Э = e (as in "met")
Ю = u (as in "use")
Я = ya (as in "yard")
So, my username would be "крэзилиттллун".
I can write English in Cyrillic. It's a very pretty alphabet and you can impress your friends.
Though once I mixed up my alphabets and accidentally submitted an assignment written in Cyrillic. Luckily, my professor spoke Serbian and could read the Cyrillic alphabet. She graded it as if it were written in the Latin alphabet, commended my abilities, and told me to be a little more careful next time.
Have fun learning!