Some people use different fertilisers for growth and blooming (including me) but others say the blooming ones are a waste of time. I'm not sure, but I keep using the ones I have simply because they work as a generarl fertiliser and I have some left in the bottle.
General advise is to use a balanced fertiliser where all three numbers are the same. Some fertilisers sold for orchids are not like that though so you might want to look arround.
Yet again Ray has losts of advice about fertilisers. The link below is just to his 'free information' page, because there are quite a lot of links near the top of that which relate to fertiliser, not just one that I can post here.
First Rays' Free Info