The Blonde from Barsoom — Robert F. Young

When scifi writer Harold Worthington Smith imagines himself on Mars, rescuing a buxom princess from green-skinned aliens, the fantasy suddenly becomes all too real. Harold finds himself stranded on the red planet's dead sea, facing down an army of fearsome Martians astride six-legged beasts. With the curvaceous blonde princess at his side and only a faithful guard dog for company, Harold battles through one peril after another in a thrilling escape across the Martian landscape. But can Harold write his way out of this predicament and back to his typewriter on Earth?