BASIC RELAY CONNECTIONS AND POWER

Hi forum users, i'm attempting my first arduino automation project and i'm a beginner, so this question I should imagine will be an easy one for alot of you. I have a arduino uno and a sainsmart 5v 8 channel relay (see image.jpg) I have successfully wired this relay to the uno, grd from the relay to the ground on the uno, the following 8 pins (In1-8) to digital pins on the arduino the last pin in the series (vcc) I then connect to the 5v on the uno, I have written a quick program that basically just turns the pins on and off the red light comes on the relay so I know this is working correctly. My problem is I have only a very very basic understanding of electronics and have never used a relay, the output for each of the 8 channels has three screw holes and i'm unsure which I would wire the live, neutral, and ground in to (please see image{5}.jpg) this is the first issue, the second issue is how i power up the relay with enough current to power the appliance, there are three pins at the end which is Grd, Vcc, JDVcc, ( see image{4}.jpg ). Will i need to power the relay through these pins? and if so how would be the best means? could I cut some wire and a plug and connect it to the mains or will i need a power adapter? If so which wire (live, nutral, earth) goes to which pin on the relay? will I have to solder it to the pins? which i imagine will be quite difficult as the pins are so small. The output of the relay is 10A 250VAC / 10A 125VAC and 10A 30VDC / 10A 28VDC and input is 5v to trigger.

So basically how do i wire the output from the relay to a house hold appliance and how do i power the relay with enough current to run it. I'm looking at powering a 300watt LED Light, a humidifier, a heater, and two pc fans at 12v connected to each of the outputs on the relay, I know I may sound stupid but i'm struggling and I really would appreciate some help from the forum members and thankyou for taking the time to answer my questions :)

image[4].jpg|3264x2448

image[5].jpg|3264x2448

See these: http://www.buildcircuit.com/how-to-use-a-relay/ http://gampageek.blogspot.co.uk/2012/12/normal-0-false-false-false-en-gb-x-none.html http://arduino-info.wikispaces.com/ArduinoPower