[meebob]

In my experience, the paper weight doesn't matter all too much for whether the book feels "professional"- what I find makes a real difference is in how well you trim the book (http://homepage.divms.uiowa.edu/~jones/book/trim.html) and the quality of the materials used for the cover- no matter how nicely you bind a book, if you choose a too-flimsy material for the cover, it'll feel homemade.

[wizardforhire]

Absolutely! I bought a heavy duty paper cutter off eBay for less than $100. Just search for heavy duty paper cutter or guillotine paper cutter. They have a huge clamp and mine came with an extra blade. One of the best investments I've ever made.

[EvanAnderson]

Came here to say the same thing. I printed and bound a couple of books using the very instructions from this site back in the early 2000's. I tried to trim one of the books myself with the "chisel method" and I was displeased with how it turned out. The one that I had a buddy cut with a guillotine paper cutter at his workplace was much, much more pleasing.