The title may seem a bit mean to the newer Linux people, but its true.
Linux is a very dynamic system, you are not on Windows, where one glove has to fit all, Linux is a system that is ever changing, and changing at a rate Windows could never reach, and because of this, one glove will never fit your hand, you need to try them.
This is why I recommend a skill called "Distro Hopping" this gives you experience with systems, if you wish to learn with Linux you need this, and it will expose you to Linux in its true form.
Also Linux is just the kernel, so do not go for one which is the fastest, because the differences are minimal at the very best, we use the same kernel, you must edit it your self if it does not fit.
And this is where the distro thing comes into it.
I am an Arch boy, I love the system, but I hate Ubuntu and Mint, You maybe the other way around, or may love/hate both this reason alone we cannot tell you what you need, but we can advise you if you give the correct information to us, and we wont judge if you use a system that we don't like or feel is not the best fit, you are the ultimate decider.
You also need to remember this again, is not Windows so all your apps may not run on Linux, I personally do not use Linux on my desktop as I play games, so I must use Windows for most of them even with software like Wine.
When you come to pick a distro, take a long hard look first, What do you need it for? What do you need the system to give to you? Must you have a specific package manager? are the applications needed on that package manager? with this information, we can guide you and give you our experiences on what we have found best, take all them answers and then begin distro hopping on them suggestions and give them a try for a week.
We are here to support you, not to tell you what you want, We are not Steve Jobs or M$, you have freedom and we know that Linux is a very fragmented system, but with combined knowledge can in some way fine tune and point you to the system that maybe best.
Also, please do NOT say this system is the best, this forum has had many flame wars, they discourage new people and make us look like elitist jerks, which we are not, we are a passionate user base, treat it as one.
Hopefully this should help rule what you must ask so we can help you and support you.
(Re-written)
Distro Hopping.
So I talked about this briefly before, but this is where I will explain what it actually is.
So a lot of people ask "What is the best Linux distro" and above explains why we cant tell you, distro hopping comes in when your searching for that distro that works with you, like this for example
Question - I need a stable system for school work, but I also want to have latest technologies, What is the best distro? (This should be labeled at the end, what would you recommend from experience, not what is the best)
Answer - Well the first would be Debian, a very rock solid based distro based on the apt package manager, it is known for been used in servers for its stability, but has a very stale package base, you could try testing which is still very stable, We then have Ubuntu, based on Debian testing, it is the go to for Linux beginners because it is the best marketed distro around, this will provide a usable system out of the box without much tweaking, it is relatively stable and supports lots of hardware configurations out of the box.
Fedora is rather stable also, based on Yellowdog, updater, modified (YUM) and this uses Red Hat Package Manager (RPM) as a back-end, it is developed by Red Hat developers and is now split into 3 seperate systems, Workstation is the one you need, and is rather stable, offers good packages out of the box, but has less packages in the repo tree than debian, it is also considered bleeding edged, so software is rather new, but still stable, A more user friendly one is Korora, this is like what Ubuntu is to Debian, a pre-configured system on top of Fedora.
Arch Linux, more so Manjaro for the beginners, Manjaro is a more stable Arch Linux system, Arch Linux uses Pacman for packages and the Arch User Repo for building packages your self, it all works rather well and is a personal favorite of mine, although I prefer Arch Base, Manjaro will offer a bleeding edge system with stability and installs a lot of hard to get drivers out of the box using MWHD.
Okay so that is what a ideal question may look like, so with them answers, you go download some distros, say Ubuntu, Korora and Manjaro, use the Live CD, or if your willing, bare metal them (Install to hard drive) stay on them for a week, do not use Windows in this week unless you must, this may sound stupid but it is not, if you want to get the most from Linux, you need to stay in its ecosystem as much as possible when on the machine.
So say you try Manjaro for a few days but cant stand it, go try Korora, you may like it, so you try Ubuntu and like it a lot and it fits your needs, sit on that distro for a little while longer and see if it works, if it does chances are you have found a distro that fits you, remember you can always look online if you need help adding in kernels and tweaking the system, always remember that what you get on disc is not the final product it can always be changed.
Using these methods you will learn about Linux and find the distro you want, this was just a cut down example though, it can be a lot more complicated dependent on needs, but the community together has a lot of knowledge so don't be scared to ask us, just don't expect the best distro, its all opinionated and based on usage.