Is there any way of getting a 7GB DVD onto a normal blank DVD(4.7GB)without losing functionality with the menus and so forth! If there is what the best way of doing it and whats the best software to use to do this
The 7 gig (actually a little bigger I think) is a dual layer disk and the 4.7 is a single layer, just to clarify. You can copy it direct to a dual layer disk (Only recomend verbatim dual layer), Or there are several programs that can almost always compress a dual layer onto a single layer disk. With the few that are too large to compress down, you can usually remove something smaller (like foreign language audio tracks) and then they will compress down enough to fit (If you need all the foreign audio, then you can remove something else like dts or dolby and just leave the stereo audio tracks). It will leave all the menus and extras intact either way. You can also choose from the extras (like just get rid of the trailers/ads). Most movies will compress without cutting anything though.
dvd shrink is probably the most used and well known free program for compressing. Personally, I usally use nero recode (if you have the full version of nero 6 or 7, the you already have nero recode). About the best paid program I know that just does movie backups with compression is clone dvd. There are several others (mostly paid I think). Be aware you will need to get past copy protection too if you are backing up a commercial movie. I use anydvd (the best pay software for copy protection out there), but there are several free and pay alternatives.
Look at some of the programs here as well as the guides and tutorials.
When people talk about backing up a movie, I think it is assumed in most cases, that they will have to compress it to fit a single layer disk, so dont expect people to alway specify that when you read through these threads.