I've been testing this set for a while now, and it works quite well.
Hopefully what you will read makes sense, as I don't do many of these.
_
http://www.smogon.com/dp/pokemon/jolteon
[SET]
name: Rain Dance Lead
move 1: Rain Dance
move 2: Substitute
move 3: Thunder
move 4: Baton Pass
item: Damp Rock
nature: Timid
evs: 4 Def / 252 SpA / 252 Spe
[SET COMMENTS]
<p>With its blistering speed, Jolteon can set up Rain Dance before other Pokemon can launch their first attack. Throw in its modest movepool, and Jolteon becomes an effective Rain Dance lead.</p>
<p>If you suspect a status move coming your way, Substitute can be used to prevent it while at the same time giving you at least one free turn to set up Rain Dance if you haven't already. When you're up against a slower lead such as a Metagross, Substitute is a great move to start off with; if it uses Earthquake and breaks your sub, you can either set up Rain Dance and faint to get out of the way for a Swift Swimmer, or you can Baton Pass out to another Rain Dancer that can handle an Earthquake, like Bronzong. If you feel the need to, you can use Substitute again just in case your opponent predicts you switching and decides to use Stealth Rock.</p>
<p>While Jolteon may appear to be inferior to Electrode as a Rain Dance lead, Jolteon has several distinct advantages. The most significant of these is Jolteon's respectable Special Attack stat, and while both get STAB with Thunder, Jolteon's 30 extra Special Attack points provide a significant increase in damage. Jolteon's respectable Special Defense and its Volt Absorb ability allow it to come back in later in the game to set up Rain again once more or even make a revenge kill. Jolteon can also Baton Pass out, which not only scouts for switches, but also keeps Jolteon alive for later use while not wasting a turn of Rain Dance.</p>
<p>Physical Scarf leads spell trouble for Jolteon and its lackluster Defense, but fortunately they are few and far between. If you decide to stay in and chance it, Aerodactyl leads speed tie with Jolteon and easily take it out with Earthquake, while Jolteon will fail to OHKO Aerodactyl because of Focus Sash. Bronzong makes a great Rain Dancing partner for Jolteon, solving many of its problems; Bronzong doesn't mind any of Aerodactyl's attacking moves and can easily 2HKO it with Gyro Ball, assuming Aerodactyl has a Focus Sash. Also, the power of Bronzong's Gyro Ball will increase greatly against most of the occasional Scarf leads you will come across. Ludicolo offers great support for Jolteon (and for any Rain Dance team in general) providing some useful resists, including Ground-type attacks.</p>
Hopefully what you will read makes sense, as I don't do many of these.
_
http://www.smogon.com/dp/pokemon/jolteon
[SET]
name: Rain Dance Lead
move 1: Rain Dance
move 2: Substitute
move 3: Thunder
move 4: Baton Pass
item: Damp Rock
nature: Timid
evs: 4 Def / 252 SpA / 252 Spe
[SET COMMENTS]
<p>With its blistering speed, Jolteon can set up Rain Dance before other Pokemon can launch their first attack. Throw in its modest movepool, and Jolteon becomes an effective Rain Dance lead.</p>
<p>If you suspect a status move coming your way, Substitute can be used to prevent it while at the same time giving you at least one free turn to set up Rain Dance if you haven't already. When you're up against a slower lead such as a Metagross, Substitute is a great move to start off with; if it uses Earthquake and breaks your sub, you can either set up Rain Dance and faint to get out of the way for a Swift Swimmer, or you can Baton Pass out to another Rain Dancer that can handle an Earthquake, like Bronzong. If you feel the need to, you can use Substitute again just in case your opponent predicts you switching and decides to use Stealth Rock.</p>
<p>While Jolteon may appear to be inferior to Electrode as a Rain Dance lead, Jolteon has several distinct advantages. The most significant of these is Jolteon's respectable Special Attack stat, and while both get STAB with Thunder, Jolteon's 30 extra Special Attack points provide a significant increase in damage. Jolteon's respectable Special Defense and its Volt Absorb ability allow it to come back in later in the game to set up Rain again once more or even make a revenge kill. Jolteon can also Baton Pass out, which not only scouts for switches, but also keeps Jolteon alive for later use while not wasting a turn of Rain Dance.</p>
<p>Physical Scarf leads spell trouble for Jolteon and its lackluster Defense, but fortunately they are few and far between. If you decide to stay in and chance it, Aerodactyl leads speed tie with Jolteon and easily take it out with Earthquake, while Jolteon will fail to OHKO Aerodactyl because of Focus Sash. Bronzong makes a great Rain Dancing partner for Jolteon, solving many of its problems; Bronzong doesn't mind any of Aerodactyl's attacking moves and can easily 2HKO it with Gyro Ball, assuming Aerodactyl has a Focus Sash. Also, the power of Bronzong's Gyro Ball will increase greatly against most of the occasional Scarf leads you will come across. Ludicolo offers great support for Jolteon (and for any Rain Dance team in general) providing some useful resists, including Ground-type attacks.</p>