Once the PCB is clean and dry, drill all the remaining holes giving those components which required accurately positioned holes a final check.
Incidentally, leaving large areas of copper as shown in these photographs, is good practice for parts of the circuit which are connected to 0v (or Ground). As a bonus, it helps preserve the etching solution. Use plastic electrical tape to mask large areas from etching - ensuring it is pressed down really firmly.
While the copper is still clean and shiny, begin to solder in the components from the non-copper side. Solder the component in first, then snip off any excess wire ends. I prefer to solder parts in one at a time as this prevents missing any soldered joints.