If by car, check out the ferry schedules at either Tanjung Gemuk or Mersing. Both have ferries to Tioman, but depends on tide conditions. Sometimes they have earlier ferry schedules at Tanjung Gemuk, I used this site http://tiomanisland.com.my/tioman-island-f...erry-ticket.php to book earlier, can call up the guy to check. It'll take about 2.5 hours to reach Tioman from either Tanjung Gemuk or Mersing.

Accommodation can be cheap or very expensive, if you want no frills type, can search for chalets when arriving there, but risky. For no-frills condo type, can search for Selesa Condotel. It's located inside Berjaya Resort, but quite far away from town. Cheap, clean, quiet and can use other Berjaya Resort facilities (with fees as applicable), downsides are you will need to follow the hourly shuttle bus schedule to go anywhere from the condo, and no restaurants/cafe at the condo. Mini fridge, rice cooker and toaster provided in the rooms.

Food near high-end resort will be expensive, inside town cheaper. Rent for motorcycles is about RM 80 a day, car at RM 140 per day, inclusive fuel. Rented vehicles not allowed in certain resorts, e.g. Berjaya. Activities can be arranged with resorts or through those locals who lurk around the ferry terminal. They will arrange snorkelling/islang hopping/fishing (yes, fishing, even though it is a marine park)/etc, prices may vary about 300-600 depending on number of pax and type of activities involved.

Since the chalets are cheaper, you may not get any rooms during high season, i.e. May till Oct, and will have to search around. Berjaya has a restaurant, a cafe and a beach-side bar, prices will be higher than others of course. As mentioned by Lester1987, the beaches may vary in cleanliness depending on where you choose to stay, the beaches at Berjaya are quite clean usually, unless you swim near the river outlets there. The sea is calmer during high season as well.