я = ya, This is why I rather learn the Russian alphabet and use it, because you still need to come up with the right spellings in the Latin letter versions and for me it is more memorable in the Russian letters. "моя" is the version of "my" for feminine words, so now we know that the word for mouse in Russian is feminine: "Мышь"
You can minimize the window just a tad and stick this window in a corner of the screen, until you learn it. Use notepad and practice, top row, middle row, bottom row, then with ALT or Shift. If you decide to save something on notepad though, save it as Unicode (Endcoding). You can take a sharpie to tape and make little stickies for your keyboard if you like. Some online places sell Russian alphabet keyboard stickers. https://www.microsoft.com/resources/msdn/goglobal/keyboards/kbdru.html
That's why I use the Russian mnemonic keyboard. Every letter can be located at their English counterpart, eg. И = I, Д = D, etc. Some letters can be written by multiple characters (hence the name "mnemonic"), eg. Я = YA, Ё = YO, etc.
This makes typing in Russian very straightforward. Just type moya and you get моя.
The layouts may vary in different operating systems. The Windows 8/10 layout is detailed here.
I used this website and found it very helpful. You can change it to Russian in the settings. It is programmed to only let you progress to new bookstaves once the ones you have are fairly well-mastered--in fact, it was a program like this that tought me to type with the English keyboard when I was a kid!
ь after hushes (ш, щ, ж, ч) at the end of feminine nouns is just a spelling convention in modern Russian:
- feminine: мышь, брешь, помощь, ночь, дрожь, вещь, дичь, ложь
- masculine: марш, ковш, борщ, луч, нож, шабаш, врач, гараж, багаж
Hush consonants used to be palatalized; then Ш and Ж hardened up. Anyway, all hushes have their "softness" fixed in modern Russian, so from the point of view of pronunciation it would not matter if you spelt them with a soft sign or without it. Instead, they are spelt consistently to reflect what the word is. For example, the 2nd person singular non-past form of a verb also has a soft sign in its personal ending: «Ты видишь мышь?»
Exactly. However, if it isn't a hush consonant, and the word does not have an easily recognizable masculine/feminine suffix—use a dictionary. Months are all masculine, though.
-ТЕЛЬ is an analogue of "-er" in English and is masculine, so if you are sure it is a suffix — you are done. For example, выключатель is literally a "turnoff-er", учитель a "teach-er"
-ОСТЬ is similar to the English "-ity" and makes abstract nouns. For example, относительность is relativity.
There are some other tricks you can use — for instance, only feminine nouns end ing -ЗНЬ (боязнь "fear, phobia", болезнь "disease", казнь "execution"). However, I doubt it will pay off for a beginner. -ь-ending nouns are a minority. A small list of 20 nouns will get you through top-1000 words in Russian. About 80 nouns with genders memorized are enough for 3000 most popular words (if you use exclude a few dozen тель/ость-suffixed nouns and month names).