I've dyed my hair a reddy black a good few months ago, but now dyed it brown a week ago but I don't like it how long do I have to wait to dye it blonde?

You are over-processing your hair if you have dyed it twice already which will only lead to breakage, possibly at the scalp level which will lead to hair loss as the hair follicles sometimes never recover from that shock.

Going from dark to blonde will only be too traumatic; I would suggest you wait till you have some regrowth before dying again, maybe 3 or 4 months.

I did dye my hair the first time over 8 months ago, but thanks any ways just wanted to know how soon you could dye it again as doing like this colour at all :(

I did dye it about 8 moths ago but thanks any ways just wanted to know how long I had to wait to dye again as I really don't like this colour :(

Ok 8 months between dye jobs isn't too bad. You are going to have to use a color stripper first I would imagine... going from dark to blond is going to be very hard on your hair just like Tickle said so I would give it a few weeks anyway and use lots of deep conditioners in the mean time...

Another option for you to try without doing more damage to all of your hair would be to try highlights first. Just a few and not the big chunky ones... Again wait a few weeks first.