How much tax will I pay?

My husband earns approx €100k per annum and has all of my allowance as I am not working. We are jointly assessed.

I have been offered a job.

Am I correct is saying that on everything I earn I will pay 41% income tax & 6% Universal Charge? Will I be charged top rate PRSI also or is this individually assessed?

You should receive at a minimum a tax credit of €1650 (you and your husband might want to share total credits equally but the absolute minimum you will have is €1650) and a standard rate cut-off point of €23800. Both of these values will be used to calculate your tax.
Your salary up to €23800 will be taxed at 20% and any excess will be taxed at 41%.
Additionally, you will pay PRSI and Universal Social Charge- these amounts will depend on your income per pay period.

You can download my spreadsheet at http://taxcalc.eu/monthlyss to check the details. There is also a USC calculator at that site.