Is it:
a table of contents (outline)?
My hints won't show you who I am
a ToC is rarely listed in a ToC, but it has hints where to find something.
I'm fairly common, I'm around.
Don't look too far and I am found.
many longer books and papers have on and it's easily found since it's at the beginning (or, rarely, the end)
I can't do tricks, nor act, nor sing,
In fact, I can't do much of anything.
I'm also not known for my stunning looks,
Still, I'm found in many scripts and books.
An outline is usually designed with usage in mind, not being beautiful. Still, any bigger book usually has one, even belletristic.
Not Man, not woman, nor child can go
too long in this world without coming to know
who I am and what I'm about.
Not too sure about this one, but anyone needs to find something in a book at some point in there lives. Webpages like Wikipedia have ToCs for long pages, too, so this also applies to the "digital generation".
This isn't difficult, you shouldn't pout.
So do you know why I hint and wink?
For it is obvious, as you may think.
All a ToC does is hint you where to find something. Also, you take it for granted in any scientific or otherwise serious book/paper/webpage.
Sit and rack your brain for a bit,
My solution is missing, but you can find it.
You may think my hints don't fully apply,
but all do, and by now you may know why.
Further word plays with finding something with a ToC. I'm not sure what is meant with 'not fully apply', though.
In conclusion, I aid your work in many ways,
But not right now, no not today.
It really helps me to find something, but for this riddle its pretty useless.