I should have added, no matter what the short term effect on your score, getting negatives off should always be a first priority IMO. With the concept of bucketing the biggest jump is often whatever is the most negative factor on your score currently. But collections are often the biggest factor, especially when newer.
Keep reading around here, there is a ton of information. I had a general idea of how credit scores worked when I started reading here (long before I had an account) but I learned a lot more detail from here. As complicated as a credit score can seem, it always amazes me how often just a few items make a huge impact on a score. Although once you get a high enough score all of the little things start to make a difference.
For me it was initially Utility, I was always at 80% or higher, low CL's but I PIF each month. Dropped my Util, saw a 100 point increase and now my biggest factor is two 90 day lates that should drop in 2 weeks. I don't expect a huge jump when those drop as I am at 750+ but the only other notation for my score is again Util and I am below 10% now at all times (highly increased CL).
Good luck in your credit journey, it feels good to take an active role in improving and then maintaining your credit file. It sounds like you are on the right track.
