I'd be interested in spriting, but I've never done it before and I'd only be able to use paint, which I haven't used in like 10 years. I'm not sure how hard it is to learn or how long a sprite generally takes to make.
Paint is honestly an excellent program for spriting. The lack of transparency is kind of a pain (as you usually want to add that and therefore need to put the sprite through another program to do so), and the small number of undos can also prove to be an issue at times, but I used Paint for a significant amount of time without any troubles. Generally, if you haven't used anything else, you won't really know what advantages they have that you're missing and therefore there won't be a problem. If you have Windows 7, you're better off looking for an older version of Paint to use -- Windows XP Paint is what I was always using back when I used it, and I think it's generally considered to be the best version -- but other than that, program isn't a problem.
Spriting is less difficult to learn than it seems. Learning to sprite well -- especially without prior art skills -- takes some time, but that's just a matter of doing it over time to learn what works and what doesn't. And unless you're doing a full-on custom spriting job and completely altering a Pokémon, spriting can take as little as ten minutes (though the more time you invest, the better it generally comes out). Most of my early sprites were pretty quick copy-paste jobs, which isn't a bad place to start out at all.
Spriting on its most basic level -- fusing two Pokémon together -- is basically a matter of picking one Pokémon to use as a base, recoloring said base to the colors of the other Pokémon (unless you make a creative choice and decide it looks better with the original colors, in which case you'll want to recolor the other Pokémon), and then building off of / replacing parts from the base Pokémon using parts from the other Pokémon.
I'd explain the exact process to you myself, but I think you'll be able to understand it better from a tutorial with pictures. I'd best suggest
this spriting guide; you'll want to refer to the "Recolors" and "Splices" sections for starters, probably. If you have interest in continuing beyond that, you can look at some of the other ones.
If anything's unclear or if you have any other questions, let me know; I'll be glad to help out.