I estimate the company and product to have around 1M - 2M value. How much would I have to give away from the company if I raised 500K? How much control would I lose of the company? Would I have to report to a board of directors?
I know I only gave rough figures, but I would be interested to even have rough answers.
1) Total up your monthly burn rate (include a 20% premium for shit happens expenses) for the bootstrapped seed stage <= 300k works for most. Multiply that by a range of 9-12 months. The 9 month period is the lower bound of what you raise and the 12 month period is the upper bound of what you raise.
2) Hopefully you can give up <= 10% of the company. It depends on a per company basis. Try to find someone to lead the round at that valuation. If someone leads at that valuation, it's easier to get others in line.
3) Your goal over the next 9-12 months should be to knock it out of the park and find a groove for customer acquisition/product market fit on a small scale.
4) In 12 months you should be making good money that covers the burn rate you've had over the past 9 months that helped calculate your seed round, but now you want to lock up the market. This is where the very purpose of venture capital comes in- you have a model that works and you want to grow + lock up the market.
5) Raise the money and grow in a calculated manner. Rounds beyond the Series A I won't cover here.
Hopefully this helps some. It's just one of many strategies to look at. To some it may make sense and to others it may be absolutely wrong.
At the level of investment you are talking about you may want to consider convertible debt rather than equity. Here is a good comparison of the two:
http://venturehacks.com/articles/debt-or-equity
Regarding control, things like board seats are negotiable and will largely depend on the type of investors you raise money from. Lots more on that topic here:
http://venturehacks.com/archives#board-of-directors
It sounds like you don't have any customers or revenue at this point. If you can get traction on one or both fronts before approaching investors you will likely increase both your chances of securing investment and your valuation.