If you're talking about modloader, Find modloader's download button, and download it. Wait for the download to finish, and you have downloaded it. As for installing it, that's a completely different topic. Usually following the instructions on the page will help.
The Server has to install the mods Not You.
bearshare is not required to get minecraft mods.
You can download minecraft plugins from planet minecraft minecraft forums bukkit (for multiplayer) mods for minecraft.com mods for minecraft.net
minecrafts popular servers are pixelmon mods
you can get most minecraft mods off the minecraft mods website, or you can google.
No! Mods are short for modifications, which change the gameplay slightly. They aren't illegal, they just support only the version of Minecraft they are compiled for. Jeb is even thinking of adding "Mod Support". Although, If you are playing on multiplayer servers, you should check the rules because some servers ban certain mods/hacks. Some servers even require you to download certain mods and/or texture packs to log into them (Tekkit servers, etc.)
download it then chuck its contents in a mods folder in minecraft .jar
Minecraft mods are always free.
no
You can still add mods using a different launcher through Demo/Single player you just can't join multiplayer servers. You have to purchase a premium account for that.
Depends on your server host.
go on you tube