Starter problem or something?

Recently, had a problem with unable starting up the car, when turning the key... car didnt crank but fuelpump is good, now that everything starts.. when turning the key to fire it up, the motor jerks funny and the headlights turn off? could it be a dead battery? also what kind of batteries can i usually use, i saw 30$ 4pound atv battery at walmart... would this be usuablle