I have to admit its something i would love to do, but somewhere like the Canadain forest areas, not Scotland... I remember watching a very interesting documentary about a man who built his own log cabin there one day and just ended up living there alone off the land.
Definitely me too, I
think you may be talking about Richard "Dick" Proenneke. I watched a documentary on youtube about him and his log cabin a little while back and loved it.
OP, The things you need to really need to focus on are water, shelter/warmth and food, the rest is details. Also do you want to travel around or stay in the same place?
Water is easy, get a water filter which is easy to clean and has a good filter life. Lets say you need about 4-5L per day, that's 1825 litres minimum for the year. That or a Millbank bag and boil it.
Shelter/warmth, that will depend on whether you want to stay in the same place or move about. If you want to stay in the same place weight isn't going to be an issue so you could go for a tent that you can have a fire or stove in, this will be very valuable in the winter. If you're planning to move about then you'll want something lightweight but also durable as it'll get a lot of use, either one won't be cheap. Clothes wise there is just so much choice and differing opinions, in general though try to pick stuff that drys quickly and that doesn't a hold smells, one example is merino wool which is light, warm and doesn't stink after long use.
Food, you mention snaring and shooting, this may be tricky as you'll need permission from landowners. If you're staying in the same place you may be able to get friendly with local landowners and make a deal. If you're moving about then it'll require a lot of planning and speaking to landowners in advance. Or you could just buy it from game keepers which is probably the better bet. That's just meat, you mention a "book about what and what not to eat", so I'm assuming you want to forage for food too, this could be tricky as although books give you an idea identifying plants and mushrooms requires a lot of experience too, knowledge also weighs nothing where as books are usually heavy
What outdoor experience do you have already?
You'll probably find a more substantial knife than just a Swiss army knife. You don't want anything too big though, something with a strong 10cm blade will do for 99% of eventualities.
So many other things to consider that I could write a massive post, are you a member of any outdoor or bushcraft forums? if you are serious get on them, read and learn as much as you can and practice.