Let's see.
1. is center-right party and moderate nationalist. He was elected president two years ago under the ticket of a fiscal pact, an agreement for a more just financing of Catalonia. On 9/11, our national day, +1 million people took the streets of Barcelona claiming for independence, and when the Spanish government said "lolnope" to the fiscal pact, he called for elections with the promise of a referendum to decide the future of Catalonia.
2. is the leader of the center-left party, currently in free-fall and falling even more tomorrow. If the party gets -20 representatives, he's going to cease to be the leader. They're against the referendum and defend federalism (which is a slightly more asymmetrical version of what Spain is today, and died when Madrid's Constitutional Court deemed unconstitutional many parts of the Estatut de Catalunya in 2010). So no-damn-body is gonna vote for him, because he is neither entirely pro-union or pro-secession. His party is the local branch of a Spain-wide one, PSOE.
3. Leader of PPC, the right wing party and local branch of the Spanish PP. Completely pro-union, defends a lighter version of 1.'s ticket last election and no referendum. May take 2.'s position in number of representatives tomorrow.
4. Leader of ERC, nationalist left-wing party, they've always been pro-independence since democracy in the 1970s, and is the only local party to exist since the Second Spanish Republic and still today have representation in a parliament. They're all for the referendum, and may become the second force in the parliament tomorrow. (3-way tie)
5. Eco-socialists. Name says all. Also, they're the offspring of PSUC, the old communist party of Catalonia that ceased to be in the 80s. They also support the referendum, although their stand on independence is unclear.
6. Far right-wing, although more in relation to the other forces than anything. They support the suppression of economic fomentation of the use of Catalan and other measures, mainly in the field of culture and language destined to end with Catalan. Although the rest of their policies oscillate between left and right.
7. Independentist. That's all. He's from Valencia.