I was googling and I found this entire archive of DooM shareware. This means 2 things.
1.You can play the beta and look through the history.
2.I'm not making a stuffty guide.

3.Free...sort of.
http://www.doomworld.com/pageofdoom/shareware.htmlEnjoy.
P.s, You should know what DooM is.
P.s.s, If you can mod, I'm trying to make a community project called; cDoom.
(Community DooM) a modifacation of DooM shareware to remake levels.
inb4notthisagain