if you want to redirect to the Home Page of another SiteView you can prepare a custom Page Template and add a code like the following:
<a href="svX.do">Go to...</a>
where 'svX' is the Id of the target SiteView.
Moreover you can refer to the Jump Unit, in fact it permits to jump forward and backward within the application without modeling an explicit link. For example if you want to redirect to a specific page of another Site View after an operation chain you can use it. You have to add a Parameter Collector Unit to the target Site View and set it to the Collector Unit Property.