You've got a big job, if you're not used to this. The first fact is that most sheet music is a representation of a popular song, based on the arrangement best know. The melody line is usually not badly done, but guitar or instrumental solos are always less good, and usually simplified to a degree. A really good example is the AVB song - pick up the pieces. The horn parts when written are wooden and lacking the buzz of the song, so you have a tricky job. If you scan the wooden parts, you then have to re-write them to add in pushes and pulls, bends, twiddly bits etc, and this is always a job and a half.
Your idea will work fine, it's what most band MDs do to produce the guts of the parts they need to hand out, but the editing takes the time, as I'm sure you know. So much depends on the person who edited the dots you're working from. Some are hugely better than others. The worst one ever was the one for a Carlos Santana song. The guitarist took one look at his part and said do you want me to play this, or what Santana played - because this isn't it!
For woodwind and strings, it's not so bad, as long as you transpose them the right way for the brass and woodwind, which I've messed up quite a few times.