Make a list of wants and needs. Also realistically look at how much you are able to spend. Browse LQS's and sewing machine stores. Remember some owners trade up rather quickly if they have the financial resources, so a used machine may be a great buy. Take your time. If possible make the lookings 'outings' and treat yourself while you are out. Negotiate where possible. Take a notebook with you so you can keep track of what you like/want.
Check that the store where you buy your machine has classes and ongoing help free of charge.
You find many who are only going to recommend a particular brand over another. There are Pfaff lovers, Bernina lovers, FW lovers, etc. Find what works best for you.
Sometimes quilt guild/group members have gently used machine they want to sell and are just looking for that 'right person' to appear. Word of mouth is very helpful.
Personally I avoid the net because that is me. However there are some good buys 'out there' if you take the time to look. Estate/garage sales sometimes have great buys as the average attendee isn't into sewing/quilting. [This is where I got my good 'ol FW.]
ali