Some nice generic links to installing mods:
The Minemum guide. Unfortunately it doesn't seem to cover my current version (1.8) which I guess has a new launcher. I did find the .minecraft directory and made a backup copy as she described. However I attempted to install Mine Forge and I didn't get a new profile, probably because it doesn't work that way now or something:
http://minemum.com/installing-mods
The minemum guide does have a link to the official Forge download page, here. I actually found this page directly via Google hunts also:
http://files.minecraftforge.net/
Actually, I got my copy of the installer from here, which seems to better indicate compatibility with Minecraft 1.8:
http://files.minecraftforge.net/fml/1.8/
I downloaded the installer and ran it, and it complained that it couldn't find the minecraft folder. I eventually figured out that this was because I have my system set up with a user privs user and an admin privs user. I was installing as my user user, and it was asking me for the admin password to run the installer, then the installer was looking in the admin's user AppData folder instead of my user's AppData folder. I could manually redirect it to my user folder and everything worked.
Some guides, like the following, just give directions on installing both the Forge "client" and "server" but I haven't seen an explanation as to what either of these are. I installed both, and the server installation involved another download and took longer. Then I noticed that the minemum guide only prescribed installing the client.
http://www.wikihow.com/Install-Minecraft-Forge
When I went to get the Minecraft Forge installer, it directed me to adf.ly which seemed to require me to download Open Download Manager with a piece of malware called Search Protect. I eventually figured out that I could directly get the download by clicking "Skip Ad" in the upper right corner, the whole Open Download Manager thing was just a Trojan horse ad. I later realized that this is covered in the minemum guide at step 1 for downloading Forge, but my impatient reading comprehension had skipped that sentence.
Here is what seems to be the definitive guide for installing mods. It has a bunch of stuff at the top for one kind of installation and then a separate section for doing the installation for version 1.8. The instructions for the second section seemed to more closely match the file structure that I found for my installation of minecraft, so I did all the steps listed, including renaming everything to _Modded. I played the renamed installation and it worked. Then I installed Minecraft Forge and it didn't complain and the game still worked, but I didn't see a "forge" profile in the launcher options as described by minemum.
http://minecraft.gamepedia.com/Mods/Installing_mods
So, what I have done since is attempt to install the client again. The installer complained that I needed to run version 1.8 at least once, so something somewhere still thinks that I'm using version 1.8 instead of version 1.8_Modded. I took the path of least resistance and renamed all my _Modded folders back to 1.8 and the client installed. Now I have a profile option of "FML" which s a funny joke the first 1/2 times. When I play the game and hit esc, there is now a "mod options" button! Still no sign of the lucky block installation, which I had attempted to do on the _Modded directory, so I'm now trying to install it again.
So, while looking for the lucky block mod I kept running into sites that attempted to get me to download other software. I eventually settled on this one which seemed the most clear as to what to click:
http://www.5minecraft.net/lucky-block-mod/
This directed me to the following site which offered just a .jar file:
http://www.dl3.5minecraft.net/download.php?file=7e2819ee5ae679adf64b19afba91acfb
Both the minemum page and a different Lucky Block page (at the link below) say just to put the .jar file in the mods folder which the Minecraft Forge installer created in my .minecraft folder (and I did verify that one has been created). But I don't see Lucky Block as one of the mods when I click the Mod Options button. Also, supposedly in Creative Mode the inventory is supposed to get three lucky blocks and I don't see them either. So, I know I'm getting good instructions from the below site because the author seems to be monitoring comments. So close...
http://www.planetminecraft.com/mod/lucky-block/
Here's an alternative source that seems slightly less scammy:
http://www.minecraftmods.com/lucky-block-mod/
Eventually, googling howls of pain led me to set up the launcher to stay visible and look at the logs, where I found this message:
[14:19:53] [Client thread/INFO] [FML]: FML has found a non-mod file [1-7-10]_Lucky_Block_v5-1-0.jar in your mods directory. It will now be injected into your classpath. This could severe stability issues, it should be removed if possible.
That doesn't sound good. It found the file in the .mod directory, but it distains it as being a non-mod file.
So, despite the fact that a lot of sites seem to indicate that the Lucky Block mod is compatible with 1.8, the .jar files all seem to say 1.7.2 or 1.7.10, so it might be that I have no other option but to play an older version of minecraft. Here is one link which describes this dilemma:
http://gaming.stackexchange.com/questions/164341/how-exactly-do-i-install-minecraft-mods-and-what-is-forge
Here is one of the sites claiming that this mod works on 1.8 (as well as 1.7.10, 1.7.2, and even 1.6.4)
http://www.minecraftexe.com/lucky-block-mod/
End of story, quickly: I set up a version 1.7.10 profile, installed 1.7.10 Forge, put the 1.7.10 .jar in the mods folder and it all works great. The 1.8 copy of Lucky Block just must not exist yet.