Hi John,
Yes, as others have mentioned, you will need to be in contact with the person that will inspect your boiler if you plan to run at a club track. The boiler inspector should be able to help you out with the sequence of construction. One tip is to not solder both ends of the fire tubes too early. This will cause great stress on the boiler if both ends are fixed before the majority of the construction is done.
In general, the construction is done from the center of the boiler towards the outside. Starting with the throat plate to the outer wrapper and boiler barrel.
Here's a link to my 5" gauge boiler build, it is on several pages, so, you will have to search a little to get the entire build. Here's the first page: **LINK**
David