To keep it simple:
I recently bought a Sony A700 with the standard sony (18-70mm?) kit lens thrown in free.
Having heard of this lens' reputation I also bought (seperately) the Sony 75-300mm f4.5-5.6 A Telephoto Zoom lens which appealed to me in the store and which I am fairly happy with (even if it isn't the most easy to use lens for a newbie!).

What I would like some advice on is which other lens' (on a sensible budget) should I buy to go with the A700 & the 75-300mm?

I am aware that there are numerous threads similar to this but I'm a bit stuck on choosing, especially given I already have one (the 75-300mm) and am not sure what others would go well with as I put together some gear?

Much Appreciated!