mouseman,
What kind of sound card do you already have? I'm also assuming you mean electric guitar.
To record a guitar into a typical soundcard, you need some way to get the guitar signal into a line level signal that can be plugged into the Line In on the soundcard.
The "traditional" approach is to use a decent microphone (the most commonly suggested mic for guitar recording is
the Shure SM-57, which you can probably buy new for around $80) into a mixer or mic preamp, and take a line level signla from that into the soundcard (you'll usually need an adapter or special cable as most soundcards have stereo 1/8" minijacks for Line In and most mixers or preamps have 1/4" or XLR connectors).
Another approach is to direct inject (DI) your guitar signal -- this means having some device that you plug your guitar into which then outputs a line level signal. Most modern guitar amps have a line out. So do most guitar multieffectors and preamps. You might already have something that can get you such a signal. If not, the simplest way is to use a device called a direct box (typically well under $100). The fanciest way is one of the new crop of amp modeling devices like
the Line6 POD or
the Johnson J Station (typically about $300 or more).
The standard wisdom is that an ordinary DI guitar track sounds terrible -- lifeless and thin -- and that the only way to get a really good sound is to mic a good amp. But this takes a lot of effort getting the mic placed just right, avoding picking up ambient sounds, having to have the guitar amp loud enough to disturb the neighbors, and so forth. A POD allows you to get a really close approximation by just plugging it in and twiddling knobs, and you can monitor it at any volume. But even a dry, dull, uninteresting DI guitar sound can be improved after the fact with DirectX plugins. Of course, while you're playing it will sound dull and uninspiring, which might affect the quality of your performance (I feel like a deflated tire when my guitar sounds poor).
As far as better software "arrangers" than ACID -- depends on what you want to do. If you want to strictly use audio loops and play against them, ACID might be all you need (and it is killer for this purpose). If you want to be able to record MIDI tracks like drum parts and keyboard parts, ACID won't do you any good at all. If you want to record a four-piece band in real time, ACID won't be much good for that, either. For more general recording and arranging, you need something like Cakewalk, Cubase, Logic, n-track Studio, or one of the many other such programs out there.
-AlChuck
