I've had ISOs in a couple of startup employers, non-qualified options in a startup customer, and RSUs in a couple of public employers.
The only book I've read on stock options is _Consider Your Options_ by Kaye Thomas, which I thought was good. I do my own taxes, and there was enough detail in that book to let me figure out the tax implications of my options. (Including AMT the one time I had to pay it.)
The actual mechanics when you already have options are straightforward. You either exercise speculatively (pay real cash to turn options into shares, then hold the shares), or exercise risklessly (pay cash to turn options into shares which you sell immediately for more cash than it cost to exercise). Exercising speculatively has risks -- you pay real money for shares that then go down in value, possibly to less than the strike price, possibly leaving you with a tax bill even though you made a loss. Exercising risklessly is safe.
I don't like to speculate with meaningful amounts of money. If in doubt, sell the stock and diversify. Think of the worst case (the company crashes and you lose both your job and the value you thought the stock had). Better to not have all your eggs in one basket and sleep well. I suspect this is not a popular sentiment there, though.
The real question with options is when you're considering multiple job offers. Company A offers $100k and 3000 options. Company B offers $110k and 5000 options. How do you value the options? For a startup, the usual answer is that you can't, because there's no anti-dilution protection. If the founders want to hose you, they can hose you, by diluting your shares or by firing you right before a vesting date. So I value them at zero and take the job I like better, or the job that pays more actual cash.
(RSUs in a healthy public company are a bit different, since they have an actual immediate cash value. I value them at 75% of the current value of the stock. The 25% discount is because of vesting periods.)