I am very fortunate to have a studio where I can relax and focus on my artwork, and where I can leave half-completed projects and paintings that are drying without having to pack it all up at the end of each session. I didn't always have this, and it is such an amazing feeling. I hope I will never take it for granted.
In my studio I have a huge old government desk (it winds up and down) and a wooden easel.
You can see lots of artists' studios at the Flickr group 'My studio/sketch stuff': http://www.flickr.com/groups/863272@N25/
Sometimes the best studio is outdoors!
Materials and equipment
Ink and watercolour
Some of my materials are shown here - watercolours, ceramic dishes, sponge, pens (Lamy), pencils (Staedtler Mars Lumograph), brushes (mainly Roymac which are cheapish, and a few Winsor & Newton).
Paper, boards and tape
I'm using Fabriano Artistico 200 gsm paper (smooth) and Arches rough 300 gsm. I've taped the paper down with masking tape - the painters' tape you get from hardware stores. It says remove within 24 hours but it doesn't seem to matter with this. You have to lift it and smooth it down sometimes. I'm not stretching the paper before I use it. Just don't get tape that's a strong colour or it will distract you from the colours in the painting.
The boards I use are plexiglass and Gatorboard - both are light and stiff - and marine plywood.
You can see other people's sketch kits at the Flickr group 'Sketch kits': http://www.flickr.com/groups/863272@N25/ and travel sketch kits and journals at http://www.flickr.com/groups/travel-sketchbooks/
Having a wooden, adjustable and reasonably stable easel helps a lot. This one is Mabef.It was pretty cheap. Its disadvantage is that its legs slide out because it has a single point for tightening all the legs and the support. It is reasonably portable, though.
See my blog post 'Is oil painting easier?' for materials and equipment I'm using.
Printing supplies I've tried and liked:
'Speedy-Cut' blocks are super easy to cut. Art suppliers sell lino blocks that are hard to cut (supposed to be easier if you warm them up). Real linoleum for flooring has a bumpy texture and I haven't found a way to smooth it enough to make a good print.
Derivan water-based inks are mainly for schools but they're great for getting the hang of relief printing techniques because they are so easy to clean up and relatively cheap.
Gamblin block printing inks - oil based but wash up in warm soapy water. Work well but be careful to clean the edge of the lid or it will get stuck like concrete, and use waxed paper circles to stop it drying out. I plan to try the 'Safe Wash Relief Ink' which contains vegetable oil and is cleaned up with soap and water.