It appears to be as stated a couple posts up. И is used as and for related objects where А is used for things that are unrelated. Like how В is used for both in and on.
Though both may seem usable in that sense, I believe но is also one that sees use. Whether theyre necessary or not seems up for debate. Russian seems pretty laid back with how it operates.
Noun cases are especially nice. I love how prefixes and suffixes are a shortcut to understanding. -ого indicates a place. -ая and others also seem to ease the learning process.
It has a lot of culture references though. You cant learn russian without learning her history.
Like how красна (красный?) is red, and red can be used in many ways. The word for beautiful itself is a modification from the root "red". So like Chinese, Russian seems to be a language with extremely logical building blocks, much like Chinese.
Only with a far less complicated writing method that looks pretty gorgeous in its own right.
(Cyrillic cursive can burn, though.)
Мои [muh-EE] брат и сестра, мои мама и папа, etc.
"Мои" = plural. In Russian plural forms of pronouns usually have no masculine / feminine differences, so "my sisters", "my brothers" and "my brother and sister" = МОИ сёстры / братья / брат и сестра.
P.S. The same situation with adjectives: высокий брат, высокая сестра, высокие братья, высокие сёстры, высокие брат и сестра (высокий [vy-SO-kiy] = tall).
There should be a button at the top left near 'Tips and Notes'. It looks like a sideways switch, and it can turn the Russian to either Cyrillic or Roman. Hope this helps!