Here you go:
Who refers to the subject and can be replaced by the pronouns I,he, she, we, they. If you can use the word we, choose who!
Example:
He (who)is running the lemonade stand.
Whom refers to the object and can be replace by object pronouns: me, him, her us, them. If you can use the word him, choose whom (Hint: they both end in M)
You pay (him) whom for the lemonade.
The way I keep effect/affect separate is to remember that affect is what your face looks like. (your emotional reaction)
The bomb went off and she still had a flat affect.