Elemods has some good tutorials – basically, you’ll need to download Texmod to replace game textures (http://elemods.blogspot.com/2013/07/texmod.html). You might need ME3Explorer if you are going to install hair mods or the Kaidan ending (http://elemods.blogspot.com/2013/07/general-post-how-to-install-pcc-file.html). And if you want to change your save files, you’ll need gibbed save editor. For the purposes of most of the mods listed in the post I wrote, you’ll only need Texmod. Let me know if you need more explanation after you try those links.