Equity and Expected Value are closely related.
Equity is your 'share' of the pot.
It can also be thought of as how often you'd win the hand if the rest of the board was dealt out.
Example: If you have A
A
and I have 7
2
, then before we see the flop, you have 87.42% equity (that's how often you can expect to win. Actually, not to be nitty, but you can expect to win 87.24% of the time, but you pick up an additional 0.18% from the times we tie.)
If there's $100 in the pot your equity would be $100 x 87.42% = $87.42
So, straight away there's a possible source of confusion - equity is both a percentage, but it can also be expressed as a $ amount.
If you want to work out equities yourself, you may want to download Pokerstove or (way better in my opinion) EquiLab.
Expected Value (or EV) is a measure of how much you'll make in a particular situation, if the situation were repeated many times. Obviously, as poker players we're trying to maximise our Expected Value
Maybe start with this
article on EV and poker (Google will find you plenty of others.
)
Come back and ask questions about the bits you don't understand.
Good Luck