What back up type should I do ?
Hi first of all I have never done imaging or cloning before. Having read up a bit I am still not 100 % sure either. What I need to be able to do is restore an entire operating system of both windows and Linux making this back up once for the whole thing so it convienently slots back in how it was originally programs files and all. I can also just do a back up of windows or linux seperately if this is more sensible.
Current state - Freshly installed windows with minimal programs now added. A Freshly installed linux on a seperate partition with a few programs added also. My computer acknowledges there are 6 partitons without all being currently connected at present (they were connected before of course). I have two external memory keys and a 1 TB external hard drive. The internal partitions are the ones that actually need backing up which include the windows restoration partition , a windows user partition C: and the linux Partition 
. The goal is to have a fully functional useable restoration from these with minimal effort.
What I am aware of :- I can make a restoration USB key in case my entire main computer hard drive fails.
Where I want to back up too :- From my internal partition sources to my 1 external hard drive as a back up.
The rest I am unsure of - I think that an image might work if I take a snapshot of the whole entire computer from windows. ie - even linux with its entire operating system and its programs and files would also hopefully magically restore as well if I take the image initially from windows itself. That is to say I would end up with a restored windows and a restored linux with everything I need.
The question is : What else would I need to do to restore this complete image of approxamately 100 GB or should I do a clone instead ?
If I do a clone can I do it to my external hard drive easily ?
My intention as mentioned is to do one or two snapshots depending on Linux for all the internal partitions to my external hard drive and be able to restore by perhaps 'different' methods back again. I might need to do the restoration by individual files or via an entire image or clone depending on the computers corruption levels and my needs. Note this may or may not be possible and this is why I am asking. I only mention clone in case this is the method I should use in my situation if imaging is not suitable.
I think it is a bit dangerous taking clones if you make wrong disk selections as I have read this. This does not mean I have made a decision which is why I am still asking about it. I am a touch apprehensive about it all as I have never imaged or cloned before.
Thanks very much for your help.