The tutorials in the wiki are current and applicable.
I would suggest you check the md5sum of your downloaded media and burn at a slow rate (as slow as possible).
As far as dual booting with win7 goes, I just did one setup like this over the weekend, so I know that it works.
You may need to manually mount the windows drive, that may be causing issue. But use fdisk to list all partitions and see if they come up.