http://www.mutools.com/mulab-product.html
I've been using it for years now - great DAW, amazing built-in synths (there's a whole modular system, actually), and very accessible pricing.
I surely agree with giving ASIO4ALL a shot (go into the advanced settings and experiment with the buffer sliders). As for a DAW, I sincerely recommend you try Mulab - you can just download the free version and see how that works for you. Good luck!
I'd give reaper a try. http://www.reaper.fm/ It's got some quirks here an there but a lot of people like it.
MuLab might be easier to learn http://www.mutools.com/mulab-product.html
Probably the simplest and most universal is Audacity. You can lay down tracks but it's pretty limited after that. http://audacity.sourceforge.net/
I wouldn't think "ProTools" would fit the "Easiest" aspect. It's very flexible but very complicated. It's what professional audio people use.
Might be worth checking out MuLab. The free version is basically a simple 4 track DAW.
They've removed it now, but on their website it used to say something cute like "You will be surprised by how creative you have to be when the track count is restricted."
Mulab: http://www.mutools.com/mulab-product.html €69/€99 with their synth MUX Modular (their synth is worth it, get it).
I really like Mulab it's my favorite alternative DAW. It's modular setup is amazing. It's biggest downside is not a lot of community or tutorials out there. It's biggest upside is how low overhead it is. I recently took a vacation with a lower end laptop and was able to use Mulab on it just fine.
Renoise: http://www.renoise.com/ $75 Renoise has more tutorials and community but it has a 'tracker' interface. This can be confusing to many people. Essentially you kind of write music more like you'd write code. If you are a programmer or even like basic scripting it makes more sense.
The best thing you can do is try out the various programs and use the one that works the best for you.
Tbh, there are some programs out there that can do some pretty cools stuff that aren't in the mainstream, and too much time dwelling on others' opinions might cause you to miss out.
I'll give one example...
I personally use and love Reaper. It's free for 60 days, and then costs $60USD after that, however, it remains usable even if you don't pay, so I suppose you could say it's "free." Still, you should pay for it eventually - the developers created a dirt-cheap professional-level (Pro Tools-killing?) DAW that does all of the same things "industry standard" (Pro Tools, Ableton, Reason, etc.) DAWs do.
Outside of that, there's Audacity. Very basic, but it gets the job done. My biggest complaint with it is in editing - editing a track is "destructive", meaning you cannot go back to your project a week later and remove an effect or undo a splice. Still, it's pretty good for a beginner, and certainly less daunting than Reaper might be.
The support base for both of these is pretty large, so you won't be alone should you start with either.
The only other one I can immediately think of is MU.Lab. I've never used it, but I've heard it's quite good, and may be a decent middle ground between Audacity and Reaper (simplicity vs. functionality).
For noise, a lot of people just record their vocals out of their closets, leaving most of the clothes in. If your closet is big enough (if you have a closet...), you could probably knock out most acoustic instruments too. It's always easier to initially record without ugly reverb, than trying to remove it later.
Check out Mulab: http://www.mutools.com/mulab-product.html
Which has a free version and the full version is very cheap. Also check out the Bedroom Producers Blog. This article on the top 40 free VSTs is a good place to start.
Also 99sounds can get you going with some samples.
There is a fair amount of free and cheap software out there, the biggest problem that I find when going with the free software is a lack of documentation, lack of tutorials, and lack of community forums.
If you have the time to put into learning it, free software can be very rewarding though.