Right, so here's some things you should consider looking into for woodies:
First off, you have to understand the concept of a woodie. Generally it's a good sized layout that is packed with lateral filled turns (the laterals are 100% intentional by designer), lots of sudden moments of floater, and overall a ride that is designed to toss you around in controlled chaos.
Secondly, you have to find what style ride you're trying to replicate. The main designers for woodies nowadays are The Gravity Group, GCI, PTC, Intamin and even Gerstlauer has made a movie on woodies. Each has their own distinctive design styles, and use their own methods of supporting and transitioning.
Gravity group is more for giving a good ride, rather than looking the best. Often times their rides will utilize steel supports rather than wooden ones. Transitions are more sudden and flowing for the mostpart, and often times their layouts will feature 90* banked turns, Voyage even manages 3. A GG ride without a 90* banked turn is like not having icing on your cake!
GCI has a very specific and distinctive design style, and thus, most experienced builders believe them to be the hardest rides to replicate, for the mere fact that the company owner likes his tracks to not only look good, but have controlled force throughout. This is why using extensive design shapes, and possibly even using Newton would provide the best possible GCI layout. GCI also uses a rather complex method of supporting, that not only looks amazing, but is incredibly strong. Basically, everything about GCI is about looking good, looking complex, and giving a great ride, even if the layout may be short.
PTC is probably the easiest ride style to build. PTC bases their rides around mostly geometrical shapes. Nothing complex about that. You can make yourself a good 16 sided circle which will allow you to place a control point at every edge to give you the best amount of control. PTC's are also rather easy to support. The Auto Supporter was designed to emulate PTC structures, so that's all you will need to use, aside from going through the layout and cleaning up supports a bit.
Intamin. Intamin woodies are built similarly to their steel rides. A lot of the banked turns are properly banked to eliminate laterals, however they do toss in a few with some laterals. The first hills on the El Toro style woodies have STRONG verticals, somewhere I even read that the back car can spike to -2.0 going over the drop. The first hills are -1.5 and then -1.3, then they get progressively weaker from there. The pullouts from the drops are also intense, reaching closer to 5.2 in the front car. Intamin makes probably the most forceful woodies out there.
Gerstlauer is more of a cross between GCI and GG, so combine those two and you're good.
The most important thing with a woodie is to know that they aren't about pinning you into your seat, or into your restraints. They are about tossing you around, giving you lots of laterals, plenty of floater (probably safe to assume that most woodies don't go over -1.1) and another aspect is giving plenty of headchoppers, or basically moments where another section of tracks supports cross over giving the sensation that you are going to have your head removed.
Which brings up another important point. Generally, you will want to support your crossover points with steel I beams, like so:
http://img80.imageshack.us/img80/1379/woodsupport.jpg
I always double up mine, because real I beams tend to be the size of double I beams in NL. This provides more support for the crossover point.
Also, another important step to take when designing a realistic ride is to tunnel test. Pretty simple, all you do is highlight the entire track, push G on your keyboard, and check the Tunnel box then click OK and ride in the simulator.
With wooden rides, you will need to change the track type to the Steel Looping ride style. Wooden tunnels are excessively large, and have a tunnel opening that is way to small.
If nothing is inside the tunnel, from the lowest rail up, then you have passed the tunnel test (basically if nothing is within reach of the riders).
That in a nutshell is the basic woodie construction tips. There are TONS and TONS more, however sometimes it's best to discover them yourself.
Oh and one more thing: try to color your rides a real wood color. A good yellow/brown color is the perfect color to use.