Firstly, welcome to the UX Mastery Community!
Are you asking for yourself or someone else?
My advice would be to first consider why it is they would like to become a UX designer. What do they love about it? What is it that appeals to them? I say this because UX is a multifaceted field with multiple points of entry and very few barrier to getting started. We're lucky because we have options and can start with something we enjoy and expand from there.
For example I'm an industrial designer but the user research side of things is my favorite. I love designing products and building information architecture structures but my true passion lies in watching people and seeing what they do and how they think.
If they're not sure which facet of UX appeals to them the most, I would recommend that they start reading everything they can that is related to UX: books and blogs are the best place to start.
There's also some really useful and reasonably priced ebooks available through UX Mastery - the one called Get Started in UX is very good for beginners and I quite like Everyday UX because it looks at ten professional UX designers (one of them lives in the same city as me and used to work for my boss/mentor which I think is pretty cool) and how they got started and how they do things.
Here's the link to where you can find them:
Also, here's a reading list that I find useful right here on UX Mastery:
I'd also advise that they get on twitter and start following and connecting with UX designers and picking their brains. If we are not talking about you- I would recommend they join this community here on UX Mastery and pick our brains! This community has some very talented and intelligent people and we're all very friendly. This is a safe place to ask questions and there's no such thing as a silly question.
Hope this helps, feel free to ask me anything