The LM3909 has been obsoleted for years now and may be too expensive or hard to find (about $12 at Mouser for what used to be a $0.39 part).
You can buy LEDs that flash all by themselves (Lite-On LTL-4213-FL) but with your deadline, you likely can't source one.
The NE555 is a bipolar version of the 555 and as such is pretty rugged. Most likely you have a wiring error. Since you didn't post a schematic it is very difficult to diagnose anything from here but Google spits out all kinds of suggestions if you ask it for "555 led flasher circuit"
http://www.google.com/search?source...circuit&btnG=Google+Search&aq=1&oq=555+led+fl
Some of the simple things to check are:
If it really and truly is an NE555 (Fairchild, et all) then 9V is OK. But if it is one of the more "modern" CMOS variations then 7V is the maximum and 5V is more appropriate. Three fresh AA batteries in series would be 4.5V and be OK.
Power and ground - you must have power to the 555 (Pin 8) and a ground reference (pin 1). Also include a bypass capactior of around 10uF and 0.1uF in parallel near the power pins of the chip. Even if you are running from a battery. Watch the 10uF (1uF, 4.7uF, all OK, value not critical) as it may have polarity (electrolytic or tantilum types).
The reset pin of the 555 must be tied high (pin 4). "High" typically means to the VCC supply rail. No need for a series resistor in this case.
The compensation pin (5) really should be bypassed with something on the order of 10nF to 0.1uF.
Again, check the exact part number you have, the timing formulas are slightly different for the bipolar and CMOS versions so your RC network on the trigger, discharge and threshold pins may be out of whack.
The led should have a series resistor to limit maximum current through it to less than 20mA. In fact, 3mA to 5mA is plenty for most "modern" LEDs. Calculate the resistor size roughly as (Vcc - Vled) / 0.005 where Vled = 2V (this is the voltage dropped across the diode, can be anywhere from 1.4V to about 2.2V but 2V is a good compromise). Then find the closest standard value resistor. Or just use 1K and call it a day.
LEDs are polarized devices. Depending on the exact LED, they typically mark the body or use different length leads (assuming it has leads and isn't SMT). If you know the manufacturer of the LED, check its datasheet. I have found that some mark the anode others the cathode. From memory, and only good in a general way, for T1-3/4 and similar body styles, I believe the long lead is the anode. But with a series limiting resistor of around 1K you can't really do any harm with the LED backwards.
OK, lots of stuff here and like I said, without seeing your circuit and schematic it is all just guessing.
Good luck.
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