Spring loaded turnouts

Those would be the turnouts by Peco. You'll want to check out this page for turnout templates and all that:  http://www.peco-uk.com/page.asp?id=tempc83

One thing I recommend is that you make sure you have at least one runaround on which you can fit your entire longest train. 

I applaud your idea of using the 4.5 as staging. Don't discount the idea of using the back half as staging and the front half as more industry potential. 

Look to the prototype for inspiration - any industrial parks or similar nearby? Remember that the prototype is in this to make money, and therefore they tend to have the simplest track plans possible - complex track wastes time and money.

One thing that you can incorporate to make sure it isn't just "you flipping switches" is the idea of multiple car spots on a single spur, as related by Lance Mindheim in the "One Turnout Layout" article in this month's magazine -  https://forum.mrhmag.com/magazine-feedback-was-ezines-891776

Design it in such a fashion that when you get more room - or move someplace with more room, you can build a layout off the ends of at least the 10 ft section. 

Look to the prototype

Do you want Urban or Rural?
Crowded or Open?

Find an industrial area that you like in the real works and look at it in Google Maps.
From there you can begin creating a realistic trackplan for your space. Post it here and we can start giving ideas as well.

Look at some of Lance's Articles and perhaps his books and ideas on small switching layouts:

http://www.shelflayouts.com/ModelRailroadLayoutDesign.htm

Thanks Jeff

"check out this page for turnout templates "

 Yeah, I'd print out the peco turnout templates  and then cut out some cardboard templates to play with the track plan on the floor. Move the templates  around and connect them with masking tape for the tracks  and set cars on them till the most satisfying track plan emerges. Once you have the plan the way you want it then you can measure the outline and build the benchwork shelves. The right 3/4's  of my shelf layout is still in the tape limbo stage even though I've started laying track on the left 1/4.  I haven't used the HO versions but I've heard that Peco switches are very reliable. If you want a rural scene you should be able to fit an elevator on there without too much trouble, check out the Logansport and Indiana Northern blog on this site for inspiration.......DaveBranum

Peco

I have always used peco turnouts. Very high quality product. I love them.

I believe you can see them in action on Chris Lyon's LVN videos here: http://model-railroad-hobbyist.com/node/11187

InRail

modeling a long, gone

modeling a long, gone prototype can be hard, Insurance maps and old railroad documentation can help point you towards the correct trackplan.

Been searching

hear you go.....

http://www.loc.gov/rr/geogmap/sanborn/

Sanborn Maps

Bremner gave a good website to address your Sanborns, they are listed by state and then by city.  These maps were basically nationwide for cities where fire insurance was sold.  The maps provide data about the commercial buildings and some residences as to construction, # of stories, fire hydrant locations, etc. with the city limits of the incorporated towns and cities.  In the case of the Colorado Midland, we have found that in some areas, the railway located their facilities outside the town limit so as to not to have to pay taxes.  That can become a major problem for modelers.  The Sanborns were usually drawn early in the town history and then changes were pasted on to the original map and may be difficult to locate.

Good luck, but they are great if your area is covered.

Maps