Hi there,
some guidance, from my experience. If you get a salary offer over €60K, then you use the green card permit route. If its between €30K and €60K, and you match an occupation for which there is a demonstrated shortage (for example, a computer programmer), then you can also use the green card route for these.
Other occupations, for between €30K and €60K will generally use the work permit route where your employer has to demonstrate (through using FAS etc) that they have tried to find an EEA national before choosing you. There are a list of occupations for which permits will not be considered too. These are contained within the guidelines.
Processing times for work permits/green cards are updated usually at least a couple of times per week (sometimes nearly every day) at
www.entemp.ie/labour/workpermits. I think a green card is currently taking 2.5 weeks to process, and a work permit around about 3.5 weeks. Then, of course, there is postage time. Check out
www.anpost.ie for some sort of guidance as to postage times.
You can download an application form online at
http://www.entemp.ie/labour/workpermits/epformsfees.htm, but this will need to be printed and posted in to Dublin. Basically, if you are applying, then you just need to tick the appropriate box on the front of the form, and then fill in the payer details with your details. You will need to get a cheque that is drawable on an irish bank (I think) for the sum of €1000.
I'm not sure about entry clearance procedures. I'm certain this is only required if you are from a visa required nation. Non-visa required nationals are permitted to show up at the border with their work permit/green card (or at least that's how it worked with me) and are given the appropriate stamp.
Hope this is of some help.