Wine by itself is a bit tricky; there are ways of making it less tricky, but it is not really the level of "can someone explain step by step (on a forum)" - I can, but you will be confused - especially since what you WANT is "game. running."
There are several ways of doing this that are LESS complex:
crossover games will work. It is commercial - but they are basically the folks doing most of the work behind WINE anyway.
- that means it is a much more user friendly way of using WINE.
They used to have a free trial. Heck at one point they offered free support for a year if gas in the US went to a certain price, and it did, so they gave free copies to anyone who signed up. That was years ago, but I think that shows they're good guys who don't want to take your money for nothing.
http://www.codeweavers.com/products/cxgames/
I would actually reccomend this one, as you would get support for 6 or 12 months, and they could help you install whatever you want. If it doesn't work 100%, they would very possibly have some say in fixing it. Not saying they will, just that hey, they might.
Another way would be 'Play On Linux' which offers some ways of installing stuff on WINE - including 'installers' for many things. However, they do NOT have one for the GOG stuff. So it's not really all _that_ simple. I do mention it because it has a gui and you may be able to figure it out _given patience and time._ (I would NOT reccomend this one at this time, as you want "game. running." )
This wiki gives the last suggestion I have - winetools. It explains how to do it in Fedora. You will have to do some careful reading here - there are things in there about "it works in 2008" "brokein in 2009" "ok works again in 2010" (PARAPHRASING) so read, and analyze, and _then_ try.
http://wiki.jswindle.com/index.php/Fedora anyway. Winetricks will let you set up a "windows" environment, and even help you install some things. Not the GOG stuff, but you'll see where "install something not listed" is (I am NOT looking at it now. I can't say what it says exactly - but you will find it if you look.)
Again, the best suggestion I have for people who are using Linux who want "game. working. now." is Crossover.
If you want to get it working and understand it, Wine + Winetricks.
If you want to have a nice gui that works with some stuff and is possibly going to be a good alternative _sometime in future_ to crossover, but free, try playonlinux.