Seriously. It has everything - you can use it to follow the lectionary cycle, you can search for resources by scripture, it links to materials, liturgy, sermons and worship structures across denominations....
Good stuff.
What do you use for worship preparation?
I also almost always check
I also almost always check textweek.com.
I'm also part of an online community http://revgalblogpals.blogspot.com that has lectionary discussion on Tuesdays and sermon discussion on Saturdays.
For Christmas, I requested the first volumes of the "Feasting on the Word" series by Barbara Brown Taylor (and someone else...) that has commentary from four perspectives for every lectionary Sunday... it is AMAZING.
I also have the United Methodist Worship Planner that Cokesbury puts out that has music suggestions from all of our hymnals, solo suggestions, and ideas for liturgy from the Book of Worship.
seminary library nearby?
I stumbled upon an incredible resource less than a mile from my church in Memphis. Harding School of Religion is a small Church of Christ seminary that does not advertise here and is tucked away off of a main road. It was suggested by a friend and I found that I could have a free membership as a local pastor. Now I go there every time I preach. I NEVER looked for a particular critical commentary and they not have it and others that I had never heard of.
Check to see if there are any seminaries nearby--even if they are from a different theological perspective, they might have some great resources!