Let me first explain what Mods and Texture packs are. Mods are things that alter the games functionality. Some mods give you the ability to summon blocks that never run out in single player mode, summon monsters, and fly in both multi and single. Some mods are against server rules and will probably get you banned so it is highly suggested only to use single player mods.
Texture packs are basically skins for your world. It alters the way the game looks. If you get a patching program it will allow you to use high resolution texture packs which makes the game more appealing to the eye.
I myself am not familiar with this website but there are a few mods and Texture packs listed here.
http://www.minecraftdl.com/
This website looked promising as it advertised several beautiful texture packs.
http://www.mods-for-minecraft.com/
I am a member of this site and I believe its one of the better Mod and Texture pack sites out there.
http://www.minecraftforum.net/
Edited by Tri-Edge on June 17, 2012 at 23:05:29
In memory of .hack//Chat I say one last time: "Let's meet again sometime, in that place we love to go. The Root town of Mac Anu!"
.... .hack//kyat....we miss you dearly