It would be simpler if you didn't have this breadboard add on that presumably covers the expansion header. What is that for?
To control the relay you'd connect a Pi 5V pin to VCC, a Pi ground pin to GND, and two gpios of your choice to IN1 and IN2. Set the gpios as outputs. Setting a gpio high should operate the relay. It should work from the Pi as it claims to work with an MSP430 which is also a 3V3 device.
For the reed switches connect one end to ground and the other end to gpios of your choice. Set the gpios as inputs with their internal pull-ups to 3V3 enabled. The gpios will normally read back as 1 but will read back as 0 when the corresponding reed switch is closed.
It might be safer to connect all the gpios via 300 ohm resistors. I.e. between each gpio and IN1/2 and between each gpio and its corresponding reed switch. This will provide a level of protection if you misconfigure the gpio settings.