The options are endless. If they fancy somwhere closer to home, then Portugal would be an excellent choice. Waves for all abilities and lots of sun. I'd recommend going in the autumn as the tourists are gone and the swell in the atlantic pick up considerably. If you're not going with a dedicated 'surf operator' company, then the less out-of-the-way the better as there will be more access to hire shops if you don't have your own equipment.
If your friends fancy a surf-orientated holiday where the people take you out every dya to good spots based on your ability, drop me a personal message and I'll find the details. I'm a bit busy at work right now to dig them out. They also cater for partners who just want to chill out.
If they have somewhere specific in mind and want to check out the potential for surf, then point them in the direction of the website below.
Pick your continent and drill down to specific locations. There are bio's, photos and ability indicators for specific breaks.
The time of year to go will depend heavily on where they choose to go. Make sure they check this out before booking!