Hey Roxy ~
First, congratz on your new gear! I agree w/what a couple of posters above said, run your new gear w/your old cables for a while, say 2 or 3 months, and get really familiar w/what a few favorite tunes sound like thru that setup. THEN, try replacing them w/an upgrade, and listening to those same tunes, listening for differences. I would suggest Synergistic Research Foundations, or one from the Cardas Clear line . I have both hooked up [in different systems] and can attest that they made an immediate and noticeable difference in SQ, esp in low end and overall detail. I know, sounds counterintuitive that they could do both simultaneously, but it happened. The SRs produced more detail but less of a difference in low-end, but the Cardas Clear are amazing [AND considerably more expensive] ~ the low end extension was so much better/fuller that I backed out of changing my amp! But follow your ears, obviously...certain cables will pair better w/certain gear ~ but sticking to the tried-and-true brands, you will almost certainly hear a gain when you upgrade and spend a few dollars on cables. Not saying that some of the the lesser known cables are not good, just that it's often "safer" to spend your extra $$$ on well known brands.
And, just to make it clear, I am talking about ONLY upgrading the interconnects ~ all of mine are RCA, but of course that's a whole other conversation.
