to make skins go to miners need cool shoes

you could also use paint.NET for texture packs and paint.NET is free :) Gimp or Gimp2 I think is also free.

skins are easy to make, you can use a website like minershoes.com to make the skins. then you click on my account at the top of the page then skin, then new skin.

to make a texture pack, you use a program such as gimp or photoshop to edit the texture files in the minecraft files. then you go to my account, texture packs, then new texture packs.

for a project, you build something in minecraft, use F2 to take photos. use a website like mediafire to upload the world save, or mcedit to create a schematic of the project., then go to my account, projects, then new project

to make a mod, you need to know how to program with java. then, after testing and designing, go to my account, mods, new mod.

hoped this helped

there are tutorials on how to make these as well, check youtube