Carpentry (joinery) or Welding?

or substitute the hammer and nails for a drill and some screws

Also drill and glue.
No nails or screws.

ah yea glue. forgot glue

if it was me and i was lazy i would just use our biscuit joiner

For that I'd say 25mm thick would be about right. To make the mortices you drill through with a flat bit. A 20mm bit would be about right. Drill either end of the mortices then work your way to the middle. Clean out the rest with a chisel, watch that you don't blow through the other side when drilling and chiselling.

Onto the tenon - mark the depth and add a few mm for you to clean off afterwards. Your best cutting the tenon with a tenon saw, means that you won't need to try and clean the lines to make the joint snug. One thing to remember when chiselling the tenon - work across the grain. If you work along the grain you risk slipping onto the exposed surface or splitting the wood. When you've made each tenon slide into the mortices then you chisel each end of the mortice for wedges.
Glue and clamp everything then drive in the wedges. Tap them in, they don't need to be that tight. Wipe away the glue with a damp cloth. Leave it to set for a day, remove the clamps and plane away the bits that are sticking out. If you don't want to buy a plane then do the pegged joint and use sandpaper to clean everything up.

I've not done a pegged joint before but I have a fairly good Idea on what you'd need to do.
It's a lot easier to explain in person as there's always a few little tips and hints I forget but can drop them in while you're doing it. Sadly I'm not a Londoner so can't help in person.

Hey! Does anyone know where I can get a piece of decent, furniture-quality wood, for a coffee table I'm making? I know timber yards do fairly rough sheets of wood for most uses, but I want suttin a little finer (and cost is less of an issue because I only need one bit, about half a sheet)

Glad I found this thread, was thinking of starting one, but no need!
Im doing a fine woodwork 2 year course at the Building Crafts College. The picture is a kitchen unit front I made for the carpenters craft competition the class were entered into

Nice job but you'd show off the bevelling (?) much better if you took it from a slight angle or lit it differently.

Also - how do you open them?

Thanks bud, looking back I wish I did take a better photo of it. Theres so much natural light in the workshop it would have been hella easy to take a step either side to show the bevelling better.

The top is just a decorative panel, while the door actually does function, just a handle wasnt required. The other thing is, is the hinges are on the wrong side for a right handed person, as well as the specification given before hand. Hopefully they can appreciate it is more aesthetically pleasing this way, than having two massive chunks missing just to have hinges on the correct side.

made at work today. First attempt at lathe work