First off, using Wubi is generally a BAD IDEA. Its behaviour is unpredictable compared to the "normal" Ubuntu. I would recommend installing it properly (for you this will probably involve using UNetBootin to boot your netbook from a USB stick).
Secondly, all your files and folders won't be "copied over" to your Ubuntu install, however you do it. To access them, click "Places" on the top bar and there should be a partition labelled either WINDOWS or /dev/sda1 or NTFS something similar to one of those... This will link to the C:\ drive on your Windows install.
Thirdly, to get the internet working, you will have to first configure it, but first you will have to check you have a working driver. This is a whole separate issue, so once you've got the netbook version installed properly, I suggest you read some of the other threads about getting Ubuntu's wireless working, and if it still doesn't work then start a new thread asking that question.
To uninstall Ubuntu under Wubi, as far as I can remember you just uninstall it like any other windows programme - using Add/Remove programmes. I don't know whether this will delete your partition, but it will get rid of the desktop version. You can then re-install the network version (as I mentioned before, I would use UNetBootin or an external USB CD/DVD drive to install it properly). The option to "make it as my only partition instead of having duel partition" is in the installer but it will delete all your files from the windows install
. You should probably install the netbook version, copy your files over to Ubuntu, and THEN delete the windows install. Alternatively, back up all your documents to another drive (you do this regularly, right?
) and restore to Ubuntu after wiping the windows partition. However, from the sounds of it you're quite new to Linux, so perhaps you might want to hang on to your windows install for a bit (even if it is just to get your wireless working...)
Hope this answers some of your questions,