Some "advice" from a self confessed SLR freak.
Once you go below 20mm or above 200mm, the prices shoot up considerably for good lenses. There are cheaper ones, but the quality is poor. I'm not familiar with Vivitar equipment, but a zoom in the 24-50 range is always a good buy: it's wide enough for indoors and landscapes while also long enough for standard photos (50mm equates to the eyes natural view). The minimum f-stop for these lenses is typically f3.3 or f2.4 (at 24 mm). Remember the lower the f-stop, the better the lens quality since it indicates how much light it can "use".
For longer work, a 70/80 to 200/210 is all you'll need. Cheaper versions run f4/5.6-f8. If you go for a 70-300 then you'll only get f12/16 at 300mm which is half as much light as f8. Lens speed, or lower f-stops is essential for telephotos to avoid blur and particularly to capture movement. If you really need to go longer, then you could always buy an inexpensive teleconvertor. Remember also that you can take fabulous portraits at around 100mm, but you'll need a fast lens to get that. In my experience, the wide zoom range lenses just don't cut it.
Overall, don't buy very wide range zooms because the quality is poor. The need to pack all those glass elements inside the lens results in distortion and poor f-stops, plus one big, heavy and clumsy lens.
Also, consider what you will be photographing. I've bought all sorts of lenses in the past, including an outrageously expensive 80-210 mm f2.8 weighing over a kilo, but still find that 35-70 or preferably 24-50 is all you need most of the time. If you can, I'd suggest investing in a reallly good quality one of these as it will last you a lifetime.
Good luck
