1st house, 1st garden, bad lawn

[northernrose]

I've been struggling to get my lawn looking half decent this spring too. Between my dog and my clay soil, it's been a challenge. lol.
Countryboy gave you some great advice, btw.
Some more detailed information or photos would be great, and would help everyone here give you advice. We need to know what's causing the problems.
Some basics, however:
Sounds like some dethatching might be in order. If you have bare or yellow spots, rake those areas well, add some good compost or triple mix over those areas, and then spread a mixture of grass seed and fertilizer over the whole lawn. Water in well, a good deep soaking.