This is a commonly asked question, but not one that is easily answered. I am not going to attempt to provide a comprehensive answer here, but will make a few points and steer you to a few books and web sites that you may find helpful.
The right way to start is to read up on amateur astronomy and telescopes, and ask for advice before buying from other amateurs. You will find a diversity of opinions on what the right scope to get is. That is because there is no single perfect telescope, all scopes are compromises between light gathering capacity, optical design tradeoffs, budget limits, and portability. Many amateurs have several telescopes: a main scope with larger aperture which takes a while to set up and a smaller quick setup scope for short observing sessions.
What we do recommend against is going to a department store and plunking down $100 to $200 on a 60 mm refractor that states a power of 625x on the box. First, true telescopes are never advertised by power, but by their aperture. The cheap department store scopes also come on flimsy mounts which will never provide a steady view through the eyepiece. These scopes are sold for the Christmas buying season as well as the impulse buyer who thinks it would make a good present for their child. The vast majority of such telescopes are destined to gather dust in the closet, after one failed and frustrating attempt to see anything with it. There are good beginner scopes on the market, but you need to understand the limitations and tradeoffs of the particular scope before deciding what to buy.
In recent years, the major manufacturers have introduced a large selection of computer controlled scopes, called goto scopes. Some of the low cost goto scopes suffer from the same drawbacks as the omnipresent department store 60mm refractors by having flimsy mounts. The better models of these scopes will provide for a more positive experience, but you may find you prefer a simple scope such as a 6” Dobsonian over a scope with a lot of electronics which requires fresh batteries and time spent reading the instruction manual (usually in the dark).
Before buying your first telescopes, you need to consider the following issues:
Portability and setup time, especially for a beginner, can be very important. A scope that is a hassle to carry outside to the backyard, takes 20 minutes to set up and an hour to properly cool down may not get used very often. A widely stated truism goes "The best scope is the one you use the most."
One point that is often overlooked by beginners is that you don’t need a telescope to start observing. A simple pair of binoculars is an excellent way to start learning the nighttime sky. Many of the Messier objects can be observed in 35 to 50 mm binoculars. The best single thing you can do is to come out to NOVAC’s observing sites, check out member’s scopes, and ask questions. You will find club members out at Mickie Gordon Park, Savage Farm, and Mason Neck Park observing sites on clear nights around the new moon. Don’t be afraid to ask questions; you will find NOVAC members are always willing to help somebody else get started.
It can not be overstated just how useful it is to look at and through all types of scopes, eyepieces, and filters at many different celestial objects. One of the most frequent comments one will hear from a new member upon actually seeing the telescopes and mounts is how much bigger they are than they looked in the glossy ads in the magazines. New members are also often surprised at the variety of telescopes they find, many of which are not to be found in those same full-page glossy ads.
Rather than get into an extended discussion of the different types of telescopes, I will simply point you in the direction of some useful web sites on the net and starter books. A few web sites to check out:
Recommended Starter and Equipment Books:
For a list of many of the web's telescope buying guides, see http://www.novac.com/telescope_links/telescope_advice.html.