Another great link with plenty of resources about IL-2 and everything related to it. Highly recommended.
http://forums.ubi.com/eve/ubb.x?a=tpc&s=400102&f=23110283&m=51910959

Community Addons
Program wise I would strongly recommend download ing the "Unified Installer"
from AAA. It will make a whole range of planes flyable, as well as adding maps,
gfx and sounds.
http://allaircraftarcade.com/forum/index.php
(Nota Bene: The Unified Installer dowload is around 2 GigaBytes)
Perifials
Joystick:
Absolutely required to get any joy out of IL2. (A cheap one at the very least)
I can recommend the "Saitek x52(standard)", which has served me well over the
last 6 months. it's alot of joystick for the money, but alas, it has no Force
Feedback.
(Edit: I've used the x52 for about 2 years now and the sensors are growing
somewhat unsteady, flickering 5-10%. I've been told this can be solved
by cleaning them... something I have yet to investigate. Was the worth the
stick worth the money? Yes! All the buttons of the x52 has spoiled me royally.
The only stick that may contest the x52, is the Logitech G940, which DOES
have Force Feed Back but costs about 3 times as much ;) )
Head Tracker
A head-tracker will create an unmatched experience. People usually say it takes
about half an hour to get used to a head-tracker, but you will not play without
it after that. The list of games supporting TrackIR is ever growing, but mostly
focused on simulator style games like IL2, rFactor, Arma2.
http://www.naturalpoint.com
http://www.free-track.net
I have used both the FreeTrack and TrackIR5. They both work excellent, but if
you have the money to spare, the ease the ease-of-use and optimized performance
of the naturalpoint TrackIR makes it a price-worthy product. But do try the
FreeTrack first if you are not sure.
Pedals
Absolutely not a requirement. However, it does add an extra layer of immersion
as well as taking some work-load off your hands/fingers. Many good players just
use a joystick with a twist handle.
Online Play
Unless you have flown alot of simulators before, I would recommend that you take
your time and get to know the game in singleplayer. When you can take off and
land most aircrafts. Even when you are proficient with the aircraft, going
online means you will die againd and again. Adjust your mind to this fact and
you will do fine. It took me about 20-30 hours before I got my first online kill.
A collection of Good links for newbie Pilots
http://forums.ubi.com/eve/forums/a/tpc/f/23110283/m/9121094645
http://www.joint-ops.com/php2/index.php
http://allaircraftarcade.com/forum/index.php
[url=http://web.comhem.se/~u85627360/inpursuit.pdf]http://web.comhem.se/~u85627360/inpursuit.pdf[/url]
http://www.il2-fullmissionbuilder.com/index.php
http://forums.ubi.com/eve/forums/a/tpc/f/49310655/m/1921070116
http://www.whatsmyip.org/port
http://www.extremetech.com/article2/0,2845,2348949,00.asp
http://il2.squad.directory.free.fr/_en/
http://www.mission4today.com/index.php?name=ForumsPro&file=viewtopic&t=4233
http://www.mission4today.com/index.php?name=ForumsPro&file=viewforum&f=4
http://www.mission4today.com/index.php?name=Downloads&file=details&id=3674
http://mission4today.com/index.php?name=Downloads&file=details&id=2147

I'd like to recommend a mod by a guy named Zeus-cat, called Straight From the Farm. It's a training campaign that has really helped me. It's designed to teach new players how to take off and land on air strips and carriers. Before using this, I wasn't able to land a plane, now I am, so I highly recommend it.
http://www.mission4today.com/index.php?name=Downloads&file=details&id=2147

Very useful, thanks for all the links.

Wait, this game is multiplayer? O_O

IL2DCG (IL2 Dynamic Campaign Generator)
Yes, IL2 ships with a random campaign generator. This bit of software offers a lot more options for dynamic campaigns. Just about any aspect of dynamic campaigns can be adjusted with this puppy, from squad sizes to how quickly supply chains recover from killing blows. Kinda confusing to use, but what about this game isn't at first? I'm new to the game, yet I highly recommend it.
http://www.lowengrin.com/news.php

Maaan, mod people must be the most patient people in the world, who else would accept downloading 2GB for the UI in separate files from awful Filefront? Have not these mod-makers heard of Bittorrent? :D
/rant (sorry just had to)

Late response... but...
IL2 has a very good singleplayer experience, with loads of campains, both from developers but also community based.
But multiplayer is where IL2 grows into a really awsome experience, especially when flying in formation with a few friends on TeamSpeak.
R1: Red flight! Line abrest, heading 270.
R2: Line abreast, Red 2!
...
R2: Red 1, contact approaching, your right-fife-o-clock, high.
R1: Roger Red 1, tally 1 bandit, Me109. Red flight! Initiate starboard turn for sandwich.
R2: Starboard turn for sandwich, Red 2
...
(Like EA says... It's in the game!)

GoTo http://www.warbirdsofprey.org/
Not only are they hosting a Bit torrent of UI1.2, they have also been helping folks get it up and running. (http://www.warbirdsofprey.org/modules.php?name=Downloads&d_op=viewdownload&cid=7 )
An the Full real servers they run are a lot of fum.

If you want to try out headtracking but TrackIR is too expensive for you and you don't want to build a pointmodel which you need for FreeTrack, I recommend FaceTrackNoIR.

With this program you can use a standard webcam and it wil use some sort of imagerecognition system to track your face.

The advantages are:
- It is free.
- You don't have to build anything or modify webcams.

The disadvantages are:
- It is not as accurate as TrackIR or FreeTrack.
- It consumes more systemresources (cpu power if you want) than IR headtracking, although this can be circumvented by running it on another PC in servermode.

Note that FaceTrackNoIR now also has an IR point tracker, and, since Freetrack is no longer in development, it completley supersedes Freetrack at this point (especially now it has the freetrack 2.0 protocal which is compatible with every game that has TrackIR)

All of these links are down (at least five or six of them that I've tried). I would certainly appreciate new guidance since I'm a newbie who just got the game. Thanks!

Just downloaded the game, I have windows 10, how do I get full screen?