Hi,
I guess DS1307 is easier to use (also low cost and low pin count). DS1306 has some extra features like alarm, 2 communication methods, additional outputs (refer both datasheets for more information).
But DS1307 only support 2-wire serial interface; if it is not convenient to you and want to stick with standard SPI, use DS1306;
However datasheets give you every information on how to do the communication and it's not complex.
Hope this helps you to do the selection.