Cache Clearing And General Information

Clean everything (use either):

CopyMage::app()->getCacheInstance()->flush();
Mage::app()->getCache()->clean();

Clean specific types:

CopyMage::app()->getCacheInstance()->cleanType('config');
Mage::app()->getCacheInstance()->cleanType('layout');
Mage::app()->getCacheInstance()->cleanType('block_html');
Mage::app()->getCacheInstance()->cleanType('translate');
Mage::app()->getCacheInstance()->cleanType('collections');
Mage::app()->getCacheInstance()->cleanType('eav');
Mage::app()->getCacheInstance()->cleanType('config_api');
Enterprise_PageCache_Model_Cache::getCacheInstance()->cleanType('full_page');

Get all declared cache types:
Mage::app()->getCacheInstance()->getTypes();

Cache Types

Each cache has it's own type id, which is a Magento concept to aid management of
each type of cache, basically you would use the type id to clear by that type.
Each type corresponds to a tag or a set of tags which will be cleaned when you
clean that type. To find out the info for all the currently declared types use
the "Get all declared cache types" snippet above and var_dump() it.

All cache types are stored in config, in the path global/cache/types, so you
could also use something like the Magento Debug Toolbar Show archive.org snapshot to
inspect the config stored at that path.

Configuration

Type ID: config
Tags: CONFIG

Layouts

Type ID: layout
Tags: LAYOUT_GENERAL_CACHE_TAG

Blocks HTML output

Type ID: block_html
Tags: BLOCK_HTML

Translations

Type ID: translate
Tags: TRANSLATE

Collections Data

Type ID: collections
Tags: COLLECTION_DATA

EAV types and attributes

Type ID: eav
Tags: EAV

Web Services Configuration

Type ID: config_api
Tags: CONFIG_API

(Full) Page Cache

Type ID: full_page
Tags: FPC

Note - full page cache is normally kept in a seperate cache backend, so you
should use it's own cache manager to reliably clear it