Another vote for Tabledit -- you can download a demo from the Tabledit site if you want to try it. It is free and fully-functional. I think the registered version costs about the same as a new video game -- $50.
Tabledit is not perfect, but it can get the job done in most cases. You can create either staff notation or tab, or both. You can show slurs, ornaments, fingerings, etc. etc. etc.
Just to get an idea of what it looks like and what some of the features are, here is a short score for classical guitar that I created with Tabledit:
Finale and Sibeleus are much better programs. But they are pro-software costing hundreds of dollars -- you could run a music publishing buisness with those! And for guitarists, I think Tabledit might actually be easier
fantanstic, but it's all code-based (ugh!). Tabledit is point and click, what you see is what you get.