As with fetishes, in order to make use of (aka activate) a talen's powers, a Garou must focus his Gnosis, and Garou with low Gnosis scores may find it difficult to make use of such items.
Examples of talens are Nightshade (which, when used, turns the user's entire body shadowy black, and thus makes it easier for him to remain unseen) and Bane Arrows (which, when used against a bane, do a bit of extra damage and cause the Wyrmspawn to shriek in pain).
The IC process for creating talens is similar to that for creating fetishes. The Garou must either know the Rite Of Binding or find someone to perform it on his behalf, must prepare the binding object or objects, must find an appropriate spirit to power the talens, and must either convince the spirit to willingly surrender its freedom, or must battle it into Slumber and bind it against its will. As with fetishes, binding an unwilling spirit occasionally creates talens that are in some way cursed. (The wizard/GM will determine this, since it will be largely dependent on the roleplay.) Also as with fetishes, the steps of the project must be roleplayed. Since the creation of talens is easier than the creation of a fetish, the preparations need not be as substantial and the roleplay need not be as lengthy, but they cannot be handwaved without specific approval from the Spirit wizards.
In terms of the OOC process, the Spirit wizards need only be consulted at the outset of the project. What we want in an @mail about talens is a) what effect you want from the talen, b) what spirit you're appealing to, c) what vessel you want to use for the talen, d) what you're willing to give the spirit as chiminage, e) what other Garou are going to help you, and f) who the GM is, if you have one. It's most /definitely/ OK to talk to a wizard in pages and clarify this and/or brainstorm ideas about it beforehand; but we will want to have you +mail afterwards because we want to keep track of who has what and whether the local spirits are being overburdened and the like.