Software Suggestions, please?

For graphics Gimp is a really good piece of software, very similar to photoshop.
For audio you could try Audiacity, its the only free program I know of.

Anvil Studio is alright for music, and yeah, GIMP is decent.

GraphicsGale is an art program specialized for pixel art (a technique used frequently in older and old-style games, like the kind this site is fond of). Its free version seems to be quite good. The artists I'm working with on a non-TK project are using it and seem happy so far. It also has some animation support. Not sure if it's more or less easy to understand than Paint.net or GIMP though.

They've mentioned Paint.net and GIMP already, and both seem to be pretty powerful. I haven't liked the GIMP and haven't worked with Paint.net much, but that could just be me being used to different programs. They do have the huge advantage of being free.

Seafroggys and brenthenry mentioned Anvil, which is made for composing midi music. Midi stuff works best for old-style games unless you have enough expertise and time or money to set up better sounds, which I'm assuming is not the case. There is also LMMS, which is free last I checked and works more with loops, which you may or may not find easier.

If you prefer recording music or sound effects using microphones, electric guitars, and such, Audacity can give you a very simple, but barebones way of doing that. I use Reaper myself, but it's more advanced and you're supposed to pay $60 if you like it (but if you're willing to put up with guilt and a nag screen, you can just keep using it for free... I bought it though).

okay most softwares have been covered already

for music you could also look into modplug or impulse tracker. i recall someone using .it files for the tk

nonfree software is always superior though

I think someone (my dad, maybe?) showed me that once! I never ended up using it though, so I can't endorse or disparage nss's suggestion.