I know that was in ape language of the tecnological age
Lol! I recently watched
The colour of Magic and at one point the librarian shows just how articulate the single word "Ook" can be. ?
MIDI cables - price depends on length and make - from about R50 to a few hundred. Do you have a MIDI interface to plug in the MIDI cable to your computer? If not you may need to add one to your shopping list or make sure that your audio interface has one built in. Bear in mind if you also want to play your keyboard with the MIDI from the computer, you'll need two MIDI cables.
Interfaces - decide what features you need (mostly how many and what type if inputs) and then go looking for models with those features in your price range. To put a guitar with pickup in directly, you'll need a 1/4" instrument input. Some cheaper ones only have line-level inputs, but you need something with a bit more gain than that. MIDI we've covered. Mic inputs are nice to have, but not essential. Brands, stay away from the "computer brands" like Creative, rather look at something made by a musical electronics company - I can recommend Edirol, M-Audio and ESI and there are others like Behringer that do cheaper stuff that is fairly good.
I quite like the small all-in-one USB interfaces like the Edirol UA-25, which are fairly high quality compact units with everything the small home studio needs in one box - line, instrument and mic inputs, MIDI in and out, headphone outs and even digital in and outputs.
'Round these parts we usually recommend a programme called
Reaper - not freeware, but shareware which has an unlimited trial and costs only $50. Full featured, but fairly easy to use. I'm not sure what the scoring capabilities are on it (I'm sure others can help there). The bigger programmes like Cakewalk and Cubase are very good at scoring the MIDI instruments. There are small programmes out there (probably some freeware if you search) that can take a MIDI file and turn them into printed or PDF scores, but I have no experience of them.