Solo vs Pool mining for new crypto-currencies? I have a not-so-good miner in terms of mining, like with CPU mining with LTC, it goes to 15 kHash/s which is pretty low.

I thought nor pool mining nor solo mining will earn me much when at this speed. But what if when mining other crypto-currencies like NVC, TRC or PPC? They have a lower difficulty level and probably would yield more in solo mining.

Simple question is that, if I want to mine them, what should I do, solo or pooled? and Why?

Also, how much time approximately will it take to mine one block of any of these at this speed?
Yielding literally "more" units of one currency compared with another isn't necessarily a good thing. Would you rather have 5 Japanese Yen or 5 US dollars?

The choice between mining solo or pooled is mainly one of variance; would you rather take a chance on trying to solve a block yourself, trying for a full block reward, or would you rather earn an amount roughly proportional to the work done (and probably pay a small fee for the privilege)? Unless you have a large amount of mining capacity, you may end up with nothing if you mine solo. Most people choose to pool mine for that reason.

You may find this question of interest, discussing solo mining vs pooled.

When it comes to time to solve a block, that's a completely different question, but this might help you. It will differ depending on the currency you choose (difficulty and perhaps hashpower will be different for each).