I don't mean any kind of debilatating soreness, but just a general muscle soreness that you can feel, but doesn't hinder your movement. Does lifting weights in this condition increase risk of injury significantly? Or am I just being a wiener?

I've always been told to go down in weight and go through the motions or take an extra day off when sore. You're in this for the long haul . . .no use injuring yourself or making it miserable so you don't feel like doing anything.

Sometimes when I feel sore, just going through the motions (without weight) makes me feel better and works out the soreness, so I can do a second set normally.

drink plenty of water, warm up well, stretch, and you'll be good to go. 'Soreness' can be attributed to many different things, if you're feeling it all across the muscle bundle and not just in the insertions, that's good. If it's debilitating soreness or it seems to be sapping your strength, chances are you have a lot of lactic acid still in the muscle which needs to be flushed out. Again, water is excellent, as is massage and stretching.

lactic acid does not remain that long.^

to OP, give it 72 hours...if still sore (...and you're sure it is not an injury of any sorts) lift anyway. the delayed soreness will not last as long with subsequent lifts

What kind of split are you on? It can be detrimental to recovery to attempt to work the same muscle group too freqeuntly (i.e.- less than 48hours recovery time) and this could be a reason that you're experiencing sustained soreness.

Otherwise, it could just be that you've taken some time off or are new to the gym. If this is the case, expect to be sore for a couple weeks. It's just something that you have to work through. I almost never get sore anymore (except on legs) and sometimes wish I did. I kinda like the feeling. :P

I guess I should have clarified that I've only been going to the gym for a month now.

Split is how much time you take between working a certain group? If so, then no less than 48 hours. Usually more as I'm still working out my schedule for this to the point where it's habit.

Thanks for the tips, everyone. I was planning on taking today off, anyway. I've been stretching, though I could probably do more. I'll keep on drinking lots of water.

And, yeah, I do kinda like this feeling, too.

The current best theory is that the soreness you get the day after a workout, is a slight swelling of the muscle fibres, after they've healed/hypercompensated for the load during the workout. So, any "healing" process is already long since over when you get sore. Lifting again should not be harmful. But if you're sore, you're likely to be forced to go down in weights, and you get a less efficient workout, perhaps. So why not wait?

After a few "cycles" of working a particular muscle group, you'll rarely, or never, get sore afterwards again.