I'm not too sure what you actually want from your SQL. What do you mean by "what I need is to have groups.name and items.name combined and sorted alphabetically"?
Can you give us an example of what you want.
If your trying to sort multiple columns you can try:
Code:
SELECT `items`.`id`,`items`.`name`
FROM `items`
LEFT JOIN `groups` ON `items`.`group_id`=`groups`.`id`
ORDER BY `items`.`group_id` ASC, `items`.`name` ASC
LIMIT 10,10