How do i make a mod?

Hi all,

i may sound very nooby when i say this but...
HOW DO I MAKE A MOD!
i have a lot of free time, i just need to get experienced with jdk and netbeans and everything, can anyone give me some tips.
Also if u can tell me please what kind of mod would be the easiest to build as a noob at modding, mybe adding a new item block or crafting recipe.
U TELL ME!
also can u tell me the programs that modding for minecraft requires!

Thanks
AdamDC