Battle Moveset

A Good Moveset for Surskit would have to be this:

Attacks:

Attract
Substitute
Double Team
Water Pulse

Items Attached:

Leftovers

Preferred Nature:

Timid

Strategy Using Surskit

Surskit will have trouble in almost any battle, no matter what moveset you use. I have suggested this moveset because Surskit, having some of the poorest stats for defense/special defense, so if it gets hit, it will most likely faint. So, this is a moveset aimed to avoid as many attacks as possible.
Substitute is there to help gain a few extra turns. Attract is there to annoy your opponent by causing your opponent's pokemon to miss some moves. Double team is also there to increase evasiveness, but, you might want to consider other moves such as Toxic/Agility.
Water pulse is there for the sake of an attacking move, plus the chance of confusion. If you don't think Surskit will be able to survive against a pokemon that is faster/stronger than yours, switch.

EV Corner:

Max out the EVs in Speed for Surskit with any remaining in Special Defense & Defense

Strategy Against Surskit

Surskit's Special Defense is mere avaerage while its Defense is Poor. So if you pummel it with Physical Attacks and Super Effective attacks, you should have few problems taking this Water Skimmer down

Contest Moveset

A good Contest Moveset for Surskit would have to be this for the Beauty Contest best with Modest, Mild, Rash or Quiet Nature:

Attacks:

Rain Dance
Water Pulse
Ice Beam
Blizzard

Items Attached:

Blue Scarf

Strategy Using Surskit

If you do the attacks in this following order you should have very few problems; 1st - Rain dance, 2nd - Water pulse, 3rd - Blizzard, 4th - Ice beam, 5th - Blizzard

Locations in Games

Ruby/Sapphire Routes 102, 111, 114, 117, 120 Colosseum Trade from R/S Fire Red/Leaf Green Trade from R/S

Animé Appearences

Surskit has had two Animé Appearences. First a boy who looked identical to Max had one and it needed protecting. After that, one of the twins used it to help fight off Shadow Deoxys. Episode 325: Max & Max! Protect Surskit! Movie 7: Visitor of the Space Fissure!