Reliable long lasting batteries are eneloops. There are others. In general try to get batteries described as "2000 mAh", not more, and that have "PreCharged and ready to use" on the packaging. These are normally more durable and longer lasting than other types.
Your charger is OK as a cheap charger. The charging current is too low to damage AA batteries, but you must use it carefully. Always charge empty batteries in matched sets of 2 or 4, and stop charging after 16 hours as it says in the instructions. Do not leave batteries in the charger longer than this.