I've just been through the training with Scotrail and recently fully passed out as a Conductor.
In terms of the course length this will depend on a few things. Where is your depot? and are you an external or Internal applicant? If you are internal, you wont need the Induction, and depending on your role, you may not need the Commercial course. If you are external, expect : 1 week induction course into company, 2 weeks of Commercial training (tickets and machines), 2 weeks of Rules. This will be conducted at Atrium Court. After this, you will be sent back to your depot. Different depots can work differently from this point. Personally, I did my routes. This was about 7 weeks in total. I had to learn a lot of routes and I was taken round all the major stations and shown around. You are assessed after every route with questions so make sure you are paying attention and taking down notes. When I finished my routes i went out with my instructor. 2 days spent on traction types, and 10 days shadowing. You will be given a task book to fill out for your time with your Instructor that will cover all aspects of the role. There's a section on lineside features so make sure you have that when you are route learning so you can take note of locations you see everything at. Its all pretty straight forward to be honest. It may seem a little daunting at first, but remember its in their best interests to get you fully passed out and working trains.
Apologies if i have missed anything, Its 01:30 and im just home from a backshift. Dont hesitate to ask if you have anymore questions.