It would be fair to say that Adafruit Industries has already done a great job of documenting their DS1307 Real Time Clock Kit. In fact, their instructions are far better than anything I have to offer as it includes all sorts of files, code, bells and whistles. Nonetheless, since I document everything I make - for redundancy's sake - here is how to assemble a DS1307 RTC Kit.
Step 1: The Parts
Your kit should come with:
(x1) circuit board
(x1) DS1307 RTC DIP chip
(x2) 2.2K resistors
(x1) 0.1 uF capacitor
(x1) 32.768 KHz crystal
(x1) battery holder
(x1) CR1220 battery
Step 2: DS1307
Solder the DS1307 to the board. Make sure the notch on the chip lines up with the notch drawn on the circuit board.
Step 6: Battery Holder
Place a small amount of solder on the pad in the center of the outline for the battery holder. This will help the battery make contact with the board later.
Next solder the battery holder on the board.
Step 7: Headers
If you plan on using this in a breadboard or some sort of device that uses sockets (like an Arduino), you may want to consider soldering in headers instead of wires.
Step 8: Battery
Insert the battery with the positive side facing up (away from the circuit board).
You might now want to learn how to interface with the board. Simply go here.