if i manager 3 sites, all on the same IP address, which each have a very solid page rank, is that a bad idea? meaning, if i cross link the sites, will they not be counted as solid links since they are on the same IP address? So, if Site A has a PR 6, and Site B has a PR 6, and they link to each other, is that good? or, if they are on the same IP address, will it not count as much?
Go ahead and interlink them if they are related. Don't do it if they aren't. If you link related sites you own on the same IP address Google will count the links exactly the same (according to Matt Cutts). If you heavily interlink sites that aren't related you could get a penalty.
If it is only two websites and they have related content then there will not be a problem with the sites being on the same IP address. They will not count the link anymore if your other sites was on a separate IP address. It is only 2 sites and if they are related then you will be fine. It's not like you have 6 sites, in all different niche's heavily interlinking with one another.
The links will count of course. Just do not exaggerate with the cross linking. Also try to get as many backlinks as possible from various IPs. This will make your link profile looks more natural.