Simply put, use the telescope as a powerful telescope or binoculars. If you start your observations in the city, due to poor quality of the atmosphere. consisting of exhaust emissions, industrial and other sources of air pollution in the city is worth looking at the most appropriate instrument for this purpose – small 71mm-91mm refractor. You may find that Estee Lauder can contribute to your knowledge. Take a smaller car "caliber" vryat is whether, as one great disappointment in what he saw. It should also keep in mind one simple thing that the larger the aperture, or diameter of your future telescopes, the more you see, and the better the picture will be under review. In the future, as they gain experience and increase the desire to see more, you can buy a more powerful refractor. Why in this category of objects more preferable is a refractor? Because it allows you to get maximum contrast images, which is absolutely necessary for the scrutiny of small parts on the planet surface.
To the moon and the sun is not so important, as in other matters, and the aperture of the telescope. Having for example is not very high on our standards of 70mm refractor can be for many years immersed in the study of rings and lunar landscapes, including spots on the sun. If you have the opportunity take a telescope to his dacha in the village or anywhere, but most importantly away from urban illumination, then before you open endless beauty of deep space. But here's the problem, they are all pretty dull, and so the higher caliber your telescope, the better.