I am getting ready to sex ed in my 4th and 5th grade classrooms--AIDS and "growth and development". The g & D is pretty much body changes and periods.
By and far, kids are avidly interested and want to talk about the topic. We do AIDS with boys and girls combined and it is mainly what is AIDS, how can you get it and that you cannot get it from being in school with an HIV positive student. 4th graders see a cartoon type movie about kids going to camp and there is a rumor afoot that there will be a child with HIV there. 5th graders see the Ryan White story.
The G & D we do in groups divided by gender. Young girls are really wanting to talk about the whole period thing. The boys are more far afield and I even had questions about where the baby grows, etc. 4th grade girls and 5th grade girls and boys see a movie that talks about body changes and periods. These movies are both produced by feminine hygiene companies. They cover the basics and are good. 4th grade boys see a hygiene and body changes movie.
We send a letter out ahead of time to parents advising that we are going to do the movie. Parents are invited to preview the movie or sit in on the presentation. I have had parents contact me to see the movie which is good. THose children are more likely to have a parent follow up discussion and that is probably the most important thing.
When I talk to the girls, I bring tampons, mini pads and pads. We hand them around but they only have to touch them if they want to. The movie I use with 5th graders has a young lady in it who professes to have used tampons "from the first" and if the girls mention her, I tell them it's an option but it is probably not typical that girls use them from the first period on.
Above are two education resources. There just aren't many freebies out there any more.