I've done this. I probably went over the top too and used all PC Board tie construction, mostly because these were salvaged off the previous incarnation of my current layout effort and I was a little worried about their strength.
I used a # 6 curved turnout at the head of the ladder and then used three # 5's.
The first thing I did was print off the appropriate templates for each turnout. I then drew four lines on 2" centers along the board for the track centers and carefully lined up the the turnout templates while gluing them to a piece of 1/4 hard board.
I removed the stock rail from the three # 5's for the straight route and used a single piece of 3' rail to "connect" it all as one piece, for the diverging routes, I just made sure if I didn't carry the rail all the way to the frog (where I also left a small isolation gap) that any joints between rails were soldered over top a PC board tie.
I used some weights to hold everything in place while I marked the locations to remove the base of the rail in the long stock rail for the point rails to sit in. A quick trip to the belt sander took care of that job.
Then working my way "down" I just began to solder everything in place. It was very time consuming and tedious work. Especially since I went the all PC Board tie route. I'm glad I did though because by the time I was done I had a pretty solid and accurate yard ladder ready to install on my layout.
I used a steel ruler to try and keep everything as straight as possible.
The completed ladder.
I'm sure the method of using the PC board ties throughout was probably not necessary. However, I wanted to make sure that the track work would be pretty solid, especially as I mentioned the turnouts were being recycled for this purpose.
I should also note that a piece of track work this large can still be pretty fragile. When I carried it to the sink for a good scrubbing with some hot soapy water I carried it by one one end and let hang as opposed to trying to carry it level.Therre is still quite a bit of flex with it being unsupported and I didn't want to take the chance that it would bend or break on me.
I hope this helps.