I don't have a full answer, but here's a partial anyway --

As far as trade skills go, they all start at 0. Even when you train
at level 50 finally, you start at 0. The most points your guild will
train you for is the first 20 points of any particular trade skill.
(Sometimes I've been able to squeeze in 21, but close enough)

After that it tells you, that you must practice the skill in the real
world.

Other skills work the same way, except that after the initial 20 (again,
this number seems to vary a tad depending on the skill) but then you will
have to pay money to practice.

There are also those skills that you get because of your particular class
or race, that are given an initial 'boost'. This includes examples like
the necro's Hide skill. It's initially at Below Average, meaning you've
got a 40'ish skill in it already.

Skills that you aquire, like Dodge, Dual Wield (for other classes) start
out at a higher skill value than 0. This is diffrent for all the skills
as far as i've been able to tell.

Zelrek, Necromancer
Rallos Zek

> when doing trades, is 25 the maximum level your guide can train ? or is 25
> the maximaum skill points u can put into it?
>
> i heard if u are , for example level 15, and u put one skill point into a
> trade..your skill automatically become 15 as oppose to 1.
>
> i know it isn't a necro question but i would appreciated it if someone can
> answer it for me .