You can get a slide transfered (scanned) to disk or printed, but the two most imporant things to watch out for is removing the "dirt/dust" off the slide prior to printing and cropping at the time of printing.
Through experience I found the best results by taking them to a professional camera store and getting them to print them. Review the slide with the representative for resolution to ensure the size print you want will be able to provide the resolution you want. Also, specify within the printing instructions to clean the slides prior to printing, and mark the slide frame with pencil markings to defined the frame of the picture on the slide frame so they know exactly what you are expecting in the print. Otherwise they may crop the slide if they set it up to run through an automatic print process and you might see lint, hair, or dust in final print.
The amount of time required depends on if they do the work in-house, locally or they are shipping it out of town.
I have lots of old slides I took years ago and I started to transfer them to CD recently before the color slides start to fade. I personally clean each slide and digitally scan it using my digital photo scanner and then burn them to CD. At this point they go into my photo archive or go to the store to be printed with little concerns of cropping or "dirt."
