Deleting a synced photo or bookmark It appears when you sync pictures or bookmarks that it syncs in both directions, so if my iPhone (4s) has a bookmark that my PC doesn't have it will will be once synced, or if my PC has a bookmark then my iPhone will get it once synced.

If I want to delete a bookmark, or photo, do I need to delete it in both places so that it doesn't come back when I sync. I find it annoying that I delete it then it comes back, or that I have to look at my phone and PC when I delete things.

How to sync in one direction (which I've done with mapping CRM software)?
You shouldn't need to delete a bookmark in both locations. When you delete a bookmark from one location, on the next sync it will delete it from the other location.

The Apple KB article here explains how you can manually manage one-way syncing for Music, Movies, TV Shows, Podcasts, Books, Audiobooks, Contacts, Calendars, Bookmarks, Notes and Photos.