google it.
But on the real it's pretty easy to write a cover letter. Keep the shyt under a page, same with the resume. Just do a brief summary of yourself and what made you get into the field your in, recent history is best cuz it shows your doin shyt out here, talk about your strengths and why they'd be an asset to the position your going for, and explain why you decided to go with their company as oppose to another(try not to brownnose, just be real and if its strictly money then bullshyt a tad about growth and experience and then if you want to be bold you can talk about how the company properly compensates its employees thereby making them a place that treats people right and only deserve the best people in their employ because of it. That's if your bold, I wouldn't do it cuz my aim is to always keep it 100% neutral on paper and wow them in person with controlled energy and charisma.
Trust me, I'm an interview master.
