Try consulting with a hair stylist that specialises in colour, especially if you are planning on colouring your own naturally dark hair or have had any other chemical treatments done.
Work out the undertones in your skin. Usually, as skin gets darker, undertones get warmer. Do you have yellow, orange or red undertones?
Having darker roots can actually ease you into the blonde look and help frame the colour around your face and skin tone.
Honey, ash and grey blonde tones tend to be the most universal for warm undertones.
Toners can help get rid of that slightly yellow tone that can come from over processing
Maintenance is KEY! Due to the harsh chemical processes involved in obtaining blonde hair, there can be a few side effects resulting in dry hair, loss of curls and texture and breakage - to name a few. Try to combat that by doing all your relevant research and investing in products like shampoos for colour treated hair, steam treatments and never underestimate the power of a good conditioner.