First good luck on finding something. It is a difficult and lengthy process. In my state, many full time tenured teachers were cut, so for these long term assignments--maternity and the like-- the districts are hiring these formerly tenured teachers so they don't have to train as much.
I did one long term sub assignment. I was paid a daily sub rate, had to do lesson plans, and was given computer access (login ID /email) and a computer code for accessing the building. Like Mushy said, the district can make or break you. I had a lovely district that treated me like I was one of them. I found out later that all of the teachers (unprompted by anyone) went to the principal and superintendent and asked them both to hire me full time. I didn't mind the lower rate because the district and people were so decent. The district was also about 15 minutes from my house.
As for my position, the teacher I replaced moved to another grade so the teacher was still in the building. I was able to ask a question or two, but I was basically "winging" it.
As for a permanent teaching position, don't give up. It took me 22 months (yes you read that right), over 200 resumes and 17 interviews to find a full time teaching position. I graduated December of 2008 and just started my full time teaching position this week. I have a resume of urban/suburban experience, great transcript, good recommendations.. but the teaching cutbacks really hurt the recent graduates. Don't be put off by urban teaching, I love it! The urban districts really need people-- I'm lucky, I'm in a pretty decent area, full parking lot, security. To me kids are kids everywhere my current students have issues that my own children don't have but that's okay with me. Another plus with urban districts is after five years of service, a large amount of your school loans will be paid off. (up to 21,000)