So I recently messaged this girl on Facebook, and we had a conversation that spanned a little over a week. I ended up giving her my number (instead of asking for hers), and she texted me the next day. We've been texting for a couple days now, but we've only been talking about our interests and hobbies and whatnot. I've only gotten one laugh out of her, but then again I haven't made many attempts.

My question is, what IOI's should I look for before I can start hinting or telling her I find her attractive. And when do I ask her out on a date?

sorry bro, seems like your stuck. but it's not the end,
you shouldn't communicate with a girl by text only.. it's too lame, it DLV.
last chance is:
call her, speak about 5 minutes about things she might like.. by the chat you should neg her and disqualify her playfully. ask about her realationships with friends (not boyfriend!) and if she got special plans for the week (that way you'll know if she bussy -you wont ask her to go out on the same day)
than hit her with "tommorow i go to X (coffe shop, or any meeting place that nearby her place), how about i'll meet you there? (she answers "yes")... cool, i'll meet you there at 7:00."
if she feels that it's a bad time she'll fix you, but don't ask her "will i meet you at 7:00 becuase it's DLV)
Goodluck

I agree with darknogo, get in touch immediately or its friends-zone for you (in best case , I guess it will be more like an "online friends zone" :s)

she text you, thats an ioi! stop being a bore and asking about interests and hobbies and start asking her emotional shit like: so what do you look for in a guy? when was the last time you went on a date? dont imply you may be the one for her, she'll assume this herself, just get her emotional side working first, the rest comes naturally