I haven't donated eggs (mine aren't up to standard!), but I have been through IVF 4 times (which is essentially the same treatment).
You are given medication to downregulate your hormonal cycle in order to allow it to be controlled by hormone injections. It can take 3-6 weeks for your own cycle to be suppressed. After that you will take hormone injections for 7-10 days usually (in order to stimulate lots of follicles) - during this period you will also have some scans and blood tests to check what is happening. As the follicles come to a decent size, you will be given a final injection to ripen them, and then the eggs will be collected (or retrieved or harvested) 36 hours later. This is either under general anaesthetic or using pethadine or something - the retrieval is usually done vaginally.
The hormone injections do leave you feeling bloated and crap I'm afraid. It is much more altruistic than sprem donation. I understand that the HFEA are considering changing the rules to allow egg donors to receive payments of up to £1,000.
If you are up to giving yourself injections (you can use a sort of pen for this), then you will need a couple of visits to start the process off, usually 3-4 scans/blood tests along the way, and then there is the retrieval itself. Your donee will be on medication at the same time as you to help her prepare to receive the fertilised eggs.
Egg donors are very much in short supply, and I know that you will make another woman very happy to have the chance of becoming a mother. There is usually an upper age limit of 35 for donors, and I belive that you will be screened for certain genetic factors.
I have a dear friend who has been on the receiving end of egg donation, it can bring hope back to people who feel they will never become a mother (again, in her case).
She is SO grateful to the unknown women who donate eggs to people like her, Yorkiegirl, you are a total star to be contemplating this .
I'd do it myself if I was younger and had a blemish-free reproductive career. I gather it's not easy but knowing from her the shortage of donated eggs I'd have been willing to give it a whirl.