A while back, Marsu noted how to do guitar tabs. Can no longer find it, but was great idea! In his instructions, multiple one line staves were added. As a matter of simplification, one additional stave (with six lines for guitar) should do the trick. Cookbook instructions are as follows. Not as hard as it may sound.

1. Add new staff (Staff 2) immediately below staff in question.
2. Right click Staff 2, go to "Properties", "Visual", "Lines", and increase number of lines to 6 (unless playing banjo or guitar with broken string).
3. Copy upper staff into Staff 2. Mute Staff 2. Highlight entire Staff 2, right click. Choose "Properties", "Visibility" tab. For "Show on printed page" option, choose "never".
4. On Staff 2, immediately before first note, position cursor on relevant guitar "string" line. Insert text ("x"), use staff lyric for font (or any other font you choose or have created), and type in the number of the fret. If playing a chord, simply enter further "text" entries on the relevant "string" before the chord. (Don't worry about lining up yet).
5. Continue inserting text (e.g. fret number on relevant "string") before each of the remaining notes.
6. When done, highlight the entire Staff 2. Right click. Choose "Properties", Expression Placement. Be sure to have "Preserve Width" unclicked, and have Alignment/placement" at "next note/bar".
7. If you want "bar" lines to show on tablature, highlight each bar line, right click, choose "Properties", "Visibility" and "Always" for "Show on printed page".
8. Have not quite figured out how to add visible slurs and ties into the tablature staff yet (without making the origin note visible).

I have posted an example at http://www.psalmistry.com/nwc/tab.nwc