Lessons run for three hours a day, and are generally in the morning. You will have to prepare your materials for the lessons outside of this time. (unless you're sneaky!) Most universities have a basic range of resources, such as library and photocopier.
Class Sizes are very unpredictable and can vary from just a few to a host of 30 or 40 per teacher, in extreme circumstances. As you cannot tell how many will be attending, the best thing to do is to be aware of these possibilities, but not to worry about them. Standing up in front of a gourp of non-fluent English speakers may seem weird at first, but you get used to it very quickly and you have support from Bredex and the Romanian university, should you need it.
The three hours are divided up as the teachers decide - When I taught, I took a few classes for the full three hours, but with either a 30 minute break in the middle, or two 15 minute breaks. (depending on the age/attention span of the class!) With other classes we swapped teachers at the break. Some people team taught (2 teachers in the room - joint leading, half time swapping lead, or however they saw fit.)
OUTSIDE OF CLASSES...
Outside of classes, people generally spend a lot of time with their pupils as friends. This helps you become part of the local community, learn about the country, it's people and customs. Also it helps the pupils implement their language skills in an informal setting and gain exposure to English speaking people talking to them.
Plus they're always good fun!
In most of the universities, you will find yourself teaching pupils aged from approximately 15 years old to early twenties. Occassionally you may have to teach a younger or Older class.
Standards of English are generally good, as Romania receives both English and American cultural influences through the media and also because English is one of the two standard taught languages in schools. The courses are advertised to the public as "Conversational English", so it is best to cater preprepared materials to this sort of level. There is a chance that you may face a group of what seem more like "Beginners" or "Advanced" students, so it is best to have something prepared, just in case.
(For ideas and suggestions on what to teach, see the "teaching ideas" page.)
You are given almost complete freedom over what you teach during your time, (some groups request formal lessons, such as grammar, some just want to play games - English related ones, naturally!) but remember the idea of the courses are to offer a source of lessons which anyone can attend, in which the pupils can learn about the language and culture of English speakers.
Keep them fun and make sure you're teaching them at the right level and there should be no problems!