How is a change in Picklist reflected e.g. deleting a value?
The new picklist values will be reflected going forward. Records with old picklist values will not be changed - manually change if required
Which Objects support picklists?
Account, Prospects, Opportunities, and Prospect Roles - all support specific fields and custom fields (except Prospect roles)
How do you create picklists?
1) System config. -> Validations
2) Add -> Select Object type
3) Select Standard or Custom field
4) Add picklist values (bulk add available)