If any of these questions can be answered I will be V greatful

1. Is henna actually "good" for the hair like Ive seen written on some websites?

2. is it best to get a hairdresser to do it or could I do it easily myself?

3. If I am to do it myself (cos Im too broke for the hairdressers lol), are there any particular brands I should look out for? P.S: Im from UK so no US only brands!

4. How long does one application stay in for? Or are there diff types of permanant, semi-permanant, etc to choose from?

5. Im finking on getting Mahogany dye. Would it suit me? (Fotos of me in my fotki- see my siggy) and does the colour come out very bright?