There's a lot of threads on this discussion. You could search and find a lot more information and opinions that are probably based on more experience than what I can give you with my anser. From what I gather, the secondary is really only necessary anymore if you are looking to add some extra flavorings later or dry hopping. One benefit I have found though, is that the secondary fermentation allows you one extra step towards clearer beer. This could also be just as simple as allowing that extra time the beer has sat in secondary though and the fact that it usually sits there in cooler temps. But it does leave less sediment in my kegs if I secondary before kegging as opposed to just going from primary to secondary. The cooler temps will allow sediment to drop out easier.
Big thing though, before moving the beer at all, make sure your fermentation is done and that the beer has stayed at a final gravity for a couple of days. For me, I let my beers primary for roughly 3 weeeks. That allows the yeast to do more of it's thing and I feel I have better tasting beer for it. At the end of the day, there are still some varying opinions on the matter, but I have found no major benefit to secondary unless I'm dry-hopping or adding some other flavors, fruit, etc.
