You have to find a block, so when you are mining yourself, you have to wait till it finds a whole block, you don't get anything till you find the block.
Wait, so does that mean you are constantly finding partials? Or does it mean that it just takes a long time to compute the block.
Sorry for the newbie questions, I've been trying to read as much as I can.
Basically if you were mining with that card a year ago things would be different. Today it may take you months or years to get a block.
Look at it this way - there is a pool which totals 1 TeraHash/second. It takes that pool 12 hours to get a block and get that 25BTC reward. Your card pulls 300MegaHashes/second and is basically 3000 times slower than everyone combined in that pool. So in the long run you will need 36,000 hours to find a solution to a block which is 4 years.
My numbers are all off by a bit but its the magnitude that matters - you will have to wait years without joining a pool.
Mining bitcoin yes this would be correct. LTC difficulty is much lower and your numbers are definitely off...with that said i do agree it would take a
long time to get your own block. Pool mining is definitely the way to go.