OU Presents Rosh HaShana 
About the holiday, as well as advanced articles. Also includes a collection of audio links.
http://www.ou.org/chagim/roshhashannah/The Virtual Beit Midrash 
A series of advanced lectures on Rosh HaShana, both philosophical and halachic. A resource for the serious student.
http://www.vbm-torah.org/rosh.htm
Rosh HaShanah with Torah.org 
Project Genesis has educational resources, observances, and recipes.
http://roshhashanah.torah.org/
Torah Tots: Rosh Hashana Fun and Games 
Children's site, with background, games, and activities
http://www.torahtots.com/holidays/rosh/rosh.htm
Midrash: Rosh Hashanah 
Rosh Hashanah, halakhoth, laws and customs.
http://www.midrash.org/halakha/roshana.html
Rosh Hashana: Activity Ideas 
Includes specific activities for age specific classes and groups.
http://www.jajz-ed.org.il/festivls/tish/04.html
Rosh Hashanah in CyberSpace 
Jewish New Year resources.
http://www.cyberspaceholidays.com/roshhashanah/
Chabad.org - Rosh Hashanah 
Contains information about services, study, stories and recipes. Includes Kids section. Features Find-a-Service and E-Shanah Tovah cards. Also covers Ten Days of Repentance.
http://chabad.org/holidays/JewishNewYear/template.asp?AID=4644
A Straight or a Twisted Shofar? 
Staff at the Bar-Ilan University's Parashat Hashavua Study Center discusses what kind of ram's horn to use as a shofar.
http://www.biu.ac.il/JH/Parasha/eng/rosh/fis.html