I would suggest starting out on guitar, just so you get used to it, and later switch to bass if you still want to. With guitar, you'd become familiar with more things like chords and strum patterns. I recommend the
Squier Strat Pak because that's what I started with. Also, I don't think those packs include a video anymore like mine did, so get
this video or one that's like it. You really owe it to yourself to get a video because it's like taking a lesson from a real life teacher, except you can play it as much as you want. Assuming you go this route, just practice with the pack and the video until you're familiar with everything they teach you. Once you get to that point, that's when you'll want to look for a friendly teacher. Take at least three months of lessons, once a week. You might also want to look at tablature if you're interested in learning some popular songs. Your teacher can help you figure them out. Anyway, again, that's what I did when I started out and I highly recommend it.
Also, since the video would be teaching you a bunch, you wouldn't *really* need all that extra small stuff that comes in the pack, so I would recommend looking at a separate guitar and amp. Then just get a strap and cable, and buy strings and picks accordingly. Right now, for you, I would suggest the
Vox Pathfinder since it's small but apparently really loud (I'm really excited to try one out for myself to use for recording). For the guitar, take a look at the
Ibanez Jet King. I've heard good things about it, and it has a pretty cool indie/punk look to it. I've been playing guitar for six years and honestly this gear tempts me, so it's definitely worth a look. Let us know how your search goes!