yes based on that pic, the hose coming from the transom mount should be the top one (water flows into impeller housing).
Ok I'd make sure that your drain plugs are all in (each side of block, and exhaust manifolds) and I would fill each of the hoses for the impeller with water before firing it up. The one from the impeller to the 'stat housing, I would disconnect it at the 'stat housing and fill with water, then re-connect. The one that's from the impeller to the transom mount, disconnect it at the impeller housing and fill with water. Now this might seem extreme but it's what I have done, IF the engine was drained and is empty.... fill the engine and manifolds with water too before starting. For the engine all you have to do is disconnect the big hose from the front circulating pump at the stat housing and fill the engine with water till it spurts out of the stat housing neck, then reconnect. For the manifolds, just disconnect each feed hose at the stat housing and fill each manifold with water till it runs out the exhaust housing on the bottom of the transom mount (you'll hear it running on the ground). Reconnect the hoses, hook up the ear muffs, turn on the water and fire it up.
I like the engine to be filled as well as manifolds because that way there is no way that temps can spike up in case there is an issue with the impeller. If the engine has no water in it, the temp gauge can't register correctly. Most don't do this but it's just my perfectionism.