I've edited the OP to make it a bit more general and cover all service related spam, which includes pools.
If a new coin is released, and I create a pool for it,
am I allowed to post just one time to inform miners that a pool has been setup? eg: "pool is up at: pool url here"
Or is that classified as advertising spam?
As of now, no. It will be considered as spam.
Advertising spam is not allowed, this includes mining pools, gambling services, exchanges, shops, etc. Mining pool ops should make a thread within the Mining section of Alt Currencies. Most OP's already link to pools available so advertising your pool is unnecessary and leads to too much spam. Exchanges, shops, gambling sites, etc, should make a thread in the Marketplace section of Alt Currencies.