Buying

Im looking to buy a new used truck i want a diesel i dont know to much about them so was looking for advice on a good truck.  

Diesels are only found on three-quarter ton and up trucks, unless you would like to wait for the Mahindra light-duty.

Pros: Torque, distinctive diesel sound (if you do like it), longevity, good for towing and hauling much bigger items, fuel economy

Cons: Price, distinctive diesel sound (if you don't like it), fewer good diesel mechanics, stigma attached to diesels, may not be the best choice for cold climates, fuel availability

Ultimately, if you don't prefer a specific brand or model, a well-kept used diesel that fits your budget would probably be your best solution. I'm sure others can chime in on their views and experiences with the different makes and models.