A wooden wing should let me know if it has damage, you think?
No! In fact, a wooden wing is the hardest of all to inspect for damage. A wooden wing with structural cracking may or may not be detectable. A wooden wing with wood rot or other types of damage or failure may not be detectable by rocking or by visual inspection. I have seen spars which appeared perfectly intact, but when cut through the cross section were rotted and decayed inside.
Wood has excellent, desirable properties for aircraft construction. It doesn't fatigue. It's strong, light, workable, and with proper care can last a long time. It's relatively immune to vibration. It conforms to compound surfaces, and comes in all forms. It's glued in place. It's easily worked into complex shapes. However, it's also resistant in many ways to inspection techniques, including visual, ultrasonic, etc. One can't do magnetic particle, or dye penetrant inspections on it. Shaking a wooden structure won't tell you about it's soundness either. If it is physically broken, cracked, or fractured, it may not make a sound. Glue joints are nearly impossible to identify externally with respect to soundness and integrity. Many of the older glues used for aircraft construction have been found to be undesirable and even dangerous in comparison to modern choices...and often it's the glue that's both the strongest, and the weakest component in the construction of the aircraft. Some adhesives, including epoxies, can be extremely strong at lower temperatures, but fail entirely at higher temperatures...meaning you can have a seemingly intact structure which can quite literally come...unglued.
I've long been a proponent of pilots seeking some maintenance training and that includes inspection training. I've seen pilots walk around an airplane and certify it perfeclty servicable, only to be shocked to be shown some 30 grounding items that made it very unairworthy.
A pilot may look to see safety wire in place...but does he know if it should be safety wired in the first place...or if it's tied correctly, or the right type of wire is in place? A bolt is secured with a nut, but the washer is beneath the bolt head and not the nut...is this okay (no). How many threads should be showing through the nut? Is a fiberlock nut okay ahead of the firewall? The axle nut on the wheel assembly is secured with a cotter pin...is this okay, and is it okay to bend the ends outward, instead of around the nut? (The answer to that is that bending it the wrong way, outward, reduces the strength by more than 50%...I saw a wheel fall off of a Cessna 182 on takeoff due to that very thing, once).
Many pilots assume that the mechanic is responsible for these things, and simply do a walk around to make sure all the big pieces are still there. I've heard that very language, in fact, many times. "It will probably fly. All the big pieces are still there." This may be laziness, it may be a shortcoming because the instructor who taught them didn't know any better. I call that the heritage of inexperience...one instructor who doesn't know enough teaching a pilot who grows up to be an inexperienced instructor...who passes on this legacy of inexperience and lack of knowledge...the lack of understanding becomes legitimized (dangerously so) over time until it's deemed acceptable to not know. It's not acceptable...your life depends on it.
An excellent book which is directly applicable in the USA is called AC 43.13-1B/2B. It's applicable to US standards, but is an excellent guide no matter where you go to what's acceptable in the airplane and what's not...including how to properly inspect wooden structures, metal structures, composite structures, etc. I've always considered it required reading, and if you don't avail yourself of that information, it's to your detriment. Remember, it's well enough to look the airplane over...but do you know what it is you're seeing, or what you're looking for? You might be surprised.
You can purchase or download. The FAA has it for download at:
http://rgl.faa.gov/Regulatory_and_Gu...E?OpenDocument
and:
AC 43.13-2B Acceptable Methods, Techniques, and Practices - Aircraft Alterations
and you can get it in print for a nominal fee via:
AC 43.13 Acceptable Methods of Aircraft Repair, with new 2008 part 2B revision, ISBN-10 0884875040, ISBN-13 9780884875048, JS312617-004, AMT Bookstore, a division of Aircraft Technical Book Company
I'll add as well that I've long believed that you can get some diluted systems information from the pilot manuals for an aircraft...but if you really want to get to know the systems (and you should), then the maintenance manuals are invalueable. I've obtained them for every aircraft I've flown, and have found the information invaluable. This applies to light airplanes as well as bigger, more complex airplanes.
For example, the Cessna 206 pilot manual gives little information regarding the kidney sump tanks located at the base of the wing struts, inside the fuselage...all the 200 series airplanes through the 210 have them...and the information given for handling the fuel flow fluctuation problem they can create by their design is not only inaccurate in the pilot handbook, but can cause an unrecoverable engine failure situation.
Understanding the system and knowing that the pump return vapors are returning to the fuel tank via the same feed line that's serving the kidney tank, and how it's layed out, clearly shows why switching tanks before applying the boost pump and adjusting the mixture, is important, and why applying the boost pump first, as directed by Cessna, can make the situation worse and mean one may not be able to restart the engine at all. Knowing a little about the engine and propeller means that one understands the need to retard the throttle and avoid detuning the crankshaft...important stuff to know, but not covered in the aircraft flight manual or pilot operating handbook.
You're certainly doing the right thing seeking more understanding of the airplane. I encourage you to broaden your search and pick up the technical manuals for maintenance of the airframe, engine, and relevant components (brakes, wheels, etc). These all have good information that few pilots take the time to get to know. I see frequent discussions among private pilots all the time about engines that foul plugs...but few of them understand idle mixture, enrichment valves, proper leaning procedure. I very seldom run into pilots, including many owners, who understand the manufacturers practices and procedures for post flight runups (let's face it, were you ever taught to do one?). It's not in the Piper or Cessna manual, but it's certainly in the Lycoming and Continental operating instructions put out by the engine manufacturer...as well as a lot of other good information. Pilot manuals are idiot manuals boiled down to the minimal information, for the least common denominator...and I say that as a pilot, mechanic, and instructor.
There's a lot more to learn, and there's a lot more written in the airplane, than what's in the think little booklet in the cockpit. Know that booklet inside and out and live by it, certainly. But avail yourself also of the additional information that's out there. It's not going to contradict the flight manual (even the case of the fuel flow fluctuation procedure by Cessna, previously mentioned...that's put there as a pilot procedure, but understanding the system will give you a lot more illumination into what's going on and allow you to make informed judgement on how best to operate the airplane at a time when your options are rapidly dwindling), but support how you use the flight manual, and ultimately, it's going to give you the information and the tools to be a better aviator.