tldr; I've read lots of things about freelancing and how much to charge but all I can think of are excuses for why this circumstance is different.
I'm thinking of doing some websites updates for a friend. I've done some work like this (Wordpress) a while ago but it's been a bit and it was pro bono at the time so I didn't even do any sort of invoicing.
I'm mainly worried that I'll have to overcharge because I'm rusty so I've been tossing ideas around in my head. I estimate the time it will take me for each requested item of work I've been given but then what if it takes twice as long? Do your clients ask you to timebox certain tasks (i.e. if it takes you x hours to do it then give up)? If you can't finish a task in that time, do you still charge for that work?
As an software dev at a big 5 tech company, I'd imagine my rate should be well above $100/hour but since this isn't my wheelhouse and it would be a first time, I'm more inclined to do $50/hour (despite people saying not to discount your rate).
Why do you want to do this work? It seems outside of your skillset and wordpress is a technology that is notoriously cheap to get develop for.
If you're just doing a friend a favor and picking up a little extra cash I'd charge $50/hr and let him know you're doing it at a family and friends rate and set his expectations accordingly.
If you're trying to break into freelancing I'd just not do it and spend the time reaching out to people who have problems they'd be happy to spend 125-150/hr fixing from someone who works for a big 5 tech company.
I think it's fair to discount your rate a little, but don't over do it.
You can't charge customers for feasability research. You have to be the guy that brings the solution. A bit of R&D is okay on the clock, but you have to know you can deliver the goods before taking the contract.
It helps a lot if you have friends in the industry that can answer your questions if you're stuck. You'd be surprised what you can achieve with just the internet and paid time.
The first one can be scary, and frankly it will depend on the customer. If you have a great first customer, it may propel you for a long career as freelancer. If your first customer sucks, you might be tempted to move on. For that I can only say, good luck.
The thing the experts always say is not to charge by time, but by delivered value. I haven't got there yet, and my clients seem to prefer to work with a time-based rate. YMMV.
But ... I do adjust my hours according to my productivity. So, if I need to study up on something, I generally won't charge the client for that (or not all of it) if it's reasonable that I should already know it. On the other hand, if I've been pumping out great code for the last 4 days solid, then I'll still charge a full day for the fifth day when I get a bit less done.
Just charge whatever you're comfortable at. The people who tell you not to discount are the ones who will be competing with you. $50/hour is a good deal for WordPress. You can always charge more later.
One of my mistakes was charging past my comfort zone, where I ended up too intimidated to even start working and rounded down my fees.
At a higher level, you'll be charging by value. But for now, main priority is you don't lose money and your client doesn't lose trust.
Well there's how much you might be able to charge as a developer (and the amount of money you'd have to make as a freelancer to account for things that full-time jobs typically provide, like benefits, etc), and then there's what you can charge in a particular situation.
Is your friend likely to be able to pay you, say, $4000 for website updates? (40hr @ $100). How about $2000 (40hr @ $50)? You know this person better than we do.
Self employment has much higher overhead. $50/hr is too low.
Estimates w/ disclaimers are good. Quotations are not. You're not laying tile.