Ok, well Im gonna reccomend the unified installer (UI) 1.1.1. This download contains the B29Silverplate as a part of it, and is a good place to start.
The UI is by no means a compilation of the best mods available, simply consider it a mod starter pack. Its a big file but i think you said you downloaded it already so hopefully you wont need to download it again.
Anyway, you need the Il-2 1946 version 4.08. I think its usually 4.07 out of the box, 4.08 can be found here
http://www.gamershell.com/download_17669.shtml
Then install that as per the instructions given. (note: if your using vista dont install your game on C:/programfiles, your UAC will probably give you jip.)
At this point it might be a good idea to back up your install incase something goes wrong, literally make a copy of your Il2 folder and rename it something like 'vanilla il2' Then if you make a mistake you can just start again using your vanilla file rather than reinstalling from the cd.
(whenever downloading new files or editing old ones its a good idea to back up whatever files your editing)
Once youve got that done you can then install the UI1.1, just simply a case of downloading all the zip files (8 of them i think) pointing the extractor at your il2 root folder and letting it go.
UI1.1 is here, as well as a list of mods that are included
(The link is inoperative)
then you'll need the patches for 1.1.1, just some fixes for any bugs in the UI1.1
(The link is inoperative)
Once thats done your ready to go, you will have your b29 silverplate as well as a host of new maps and new planes.
Note, you cannot install any mods without first installing the UI, the sound mod or the mod activator.
What these to is open up your game for modding, after youve taken these steps you will find some new folders inside your il2 game folder, namely MODS and files, as well as a version switcher and some 6DOF files. dont worry bout 6DOF stuff unless you use track IR or freetrack. Your version switcher will allow you to turn mods on and off, and switch between 4.08 and 4.09, many online servers allow 4.08 only as 4.09 is a beta patch.
You can then download and install any other mods you can find on the site that arent in the UI1.1, like the fairey battle or the new spitfires. And the wellington and lancaster bombers that are currently in progress, and the much anticipated WW1 expansion coming soon.
But i would check if its in the UI1.1.1 before downloading, e.g. theres no point reinstalling the b29silverplate because its in the UI1.1.1
Most other mods USUALLY just involve adding a folder to your newly acquired MODS folder and a small text edit in an ini file.
Ive said it before and I'll say it again, the golden rule is to READ EVERYTHING before installing anything.
Right i really think thats as clear as I can get
but dont hesitate to ask again.