anyways i got gmod10 a few days ago and i have some questions.
   1.how come some props don't appear when i click them on the prop list. this mostly happens in comic props. also, what does the dog do.
Could be due to faulty files.
The Dog is a character, seriously, play the half life series for epicness.
  2. How come when i make a server nobody comes? do my servers work?
You'll need to forward your ports most likely. You can goto your router page and forward the port 27015 to UDP.
  3. When i join servers, i see a bunch off big red flashy error signs everywhere.
That means you do not have that prop, usually if you see those errors, just walk up to someone ask what it is, and where do you download it.
  4. Where do i download: SWEPS to
   Maps to
   New tools to
   etc.
\Program Files\Steam\Steamapps\<username>\garrysmod\garrysmod\
Maps goes in maps, if you see a folder with a info.txt file in it that has the word like "addon information" in that, then put it in addons. Anything else, read the readme.
   5.are there any default admin sweps put in and how do i acsess them.
Flechette gun and Manhack. Press Q and then click weapons.
  6. and finally, how can i make some of the hl2 vehciles like combine helicopter work?
Q>NPCs> see if Combine Helipcopter is in there.
Also no, Gmod 10 will stay gmod 10 unless there is a huge revamp and like if he rewrites everything.
There is no gmod 11.