You can make any drawing a template. Go to 'Save As..' and I think you'll find an option for the template... and you'll be able to set this as the default.
I'm not sure a traditional AutoCAD style titleblock will make the same sense in SketchUp. Perhaps if you are using the drawing for 2d slices it might work, or if the background is the titleblock for watermarking purposed.
Layout (not in the free version) is much better for presentation / drawing organization than SketchUp.
I do what Mike suggests: I have a template file that has boilerplate title block text in the upper left hand corner. It also has my favorite style settings, etc. Note that SU supports "screen text" - text that is stationary reltive to the screen - but not "screen geometry". So you can't draw a box around it (unless someone knows a cool trick that I don't know). CB.
-- Clark Bremer Minneapolis Proud Member of the TFG