Zinc oxide (ZnO) thin films were prepared by a sol-gel method. The structural and electrical properties were investigated by varying drying and annealing temperatures. The thin films were coated (250 nm) by spin-coating method on glass substrates. The optimum drying temperature of ZnO thin films was 300$^{circ}C$ where the resistivity was the lowest and the preferred c-axis orientation was the highest. The annealing was carried out in air and inert atmospheric conditions. The degree of the preferred c-axis orientation was estimated. The highest preferred c-axis orientation was recorded at 600$^{circ}C$. The preferred c-axis orientation and grain growth resulted in the mobility enhancement of the ZnO thin films, and the lowest resistivity was 0.62${Omega}{cdot}cm$ at 600$^{circ}C$.