Basically, to connect to your computer without latency probs you need some sort of interface. I don't have any experience of others but am using a Line 6 Toneport GX. It cost less than £70 brand new and comes with loads of software for recording and stuff. I'm just using it plugged into an old laptop PC and the Podfarm software included is awesome. If you can't get the tone you want it doesn't exist!!!
Even with a crappy old acoustic guitar I can get anything from a rich, Gibson Songbird sound to Eddie Van Halen tones if I want (I just wish there was a 'talent-boost' button so I could play as well as Eddie LOL). There are lots of pre-sets and you can alter these or make your own tones - infinite variations available - then just plug it into your amp (or headphones if you're practicing at home) and make some good noise

I only just started using this so can't really offer much advice other than it is reeeaaal good value for money and works great with no latency on a very ordinary laptop PC and with the added advantage that you can make a shit guitar sound good

but only if you can play it and there is a magic way to learn this too! It's called ...... practice

Seriously folks, all the technology in the world won't help you to play but it can sure help you to get the best outta what you got.