Nomads
Its a fairly wide ranging topic that would warrant a web page, Ive never searched but im sure there is something. I will presume you have a sling load rating, your instructor or check pilot is the person you should speak to, mainly to get the safety aspects and the hook checks fairly well placed in your procedures, a small checklist helps. Remember to calculate your density altitude.
Every load is different to fly and every load is something valuable to someone, thats why youre probably slinging it. Know the VNE limits of your aircraft that you are slinging with, it is there for a reason.
Techniques vary depending on the length of the line and your use of mirrors or vertical reference. Never carry pax unless they are critical to the sling load and don't lift over populated areas or people, I don't know your level of experience so I don't want to tell you how to suck eggs.
An experienced external load pilot would be the right person to have a chat to, they can explain the different rigging techniques that are just as important as flying the load. I hope this is of some assistance, good luck Nomads
SL