[SOLVED] How to extrude a circle by a curve to make a tube or hose

I apollogize for asking a question that must have been asked a million times, but I searched the forums AND google until I was blue in the face with no success. I used to do this routinely in Blender many years ago, but when the new interface happened I fell off the Blender world. Now I’m trying to get back into it, but there’s much I still cannot do.
So, I have a bezier circle as one object, and a nurbs path. I think that’s what I think I remember I needed to have, back from the good old days. Then I remember there was an Extrude box where I entered the name of the curve, or of the circle, and the spaghetti happened; but I can’t seem to find how to do it anymore. T.I.A.

Select your curve which is your path, in the properties tab, go to the curve section, under bevel, select the circle as your bevel object.
Note, if you only really want a tube, you don’t need a curve as your bevel object. Simply increase the bevel depth then up the resolution to say 3 for a nice tube. The bevel object is more for when you want a specific profile for the curve.

Ah, many thanks! That worked. I didn’t understand the second point you made. And I’m only one step ahead of where I was, but still lost as to what to do now. I got these criss-crossing tubes looking very smooth --too smooth–, and I wanted to boolean-join them at a much lower resolution, but I don’t see how to control the resolution and/or where to convert them back to a standard mesh.

Starting to figure things out now… I was playing with the Resolution / Preview-U number and nothing seemed to be happening, but that was because smooth shading was masking the changes. It does work. And the cross section resolution is controlled by the Resolution / Preview U number for the bezier circle. I’m still looking for how to turn this into a mesh.

Found it! In object mode, from Object menu, the top item, Convert To -> Mesh From Curve