You'll be alright squishy! Sounds like you have 3 adults who are reasonably handy, and are all into the project. Just do your reading and research, You've already said you'll be doing more than just reading 1 article on HGTV.
Once you feel you are done research, write out the whole plan, step by step. Look for problems that may arise, questions you may still have. It is much easier to fix things in the planning stage, then after the hole is dug.
From the article--"Finally, dig out a few shallow plant pockets in the pond floor for setting aquatic plants in later. "-- I've seen them do this on HGTV shows, ughhh...
If you choose to do this, fine. however, I highly recommend NEVER putting any plants in the pond unless they are potted. You put a rootball and dirt in one of those pockets, you are just asking for a big muddy mess.
Other than that, Check for level like 100 times, then once more. You mess that up, the whole thing looks lopsided, and you have liner showing, not good. Be super meticulous building your waterfall/stream. Its not easy to get the water to flow just the way you want. When I was satisfied with the look and function of all my rockwork, I concreted it in place. made it much more stable, no rocks shifting underfoot. Still looks good, because I bought concrete dye and mixed it in with the wet cement to match the color of my rocks. Most places you can't even tell its there.
I know this was just a bunch of assorted rambling tips, but I hope it helps.
