In my opinion, the side rails of the frame are the best place to jack up the truck. If the jack has sufficient lifting height and is properly positioned, both front and rear wheels on one side can be lifted off the ground simultaneously. Jackstands can then be installed under the rear axle and at the front of the frame. Then the process is repeated for the other side. Naturally, if you only need to lift the front end of the truck, as when changing the oil, you would only need to install the front jackstands.
You can also jack under the front cross-member, but the available throw for a pump-type jack is minimal and the frame side rails are much easier to access.
The stock jack will lift the truck, however it is relatively unstable and takes several minutes and lots of elbow-grease to raise and lower the vehicle. I would recommend a 5 Ton floor jack, minimum, for greater ease and safety.