ISO: dough preparation tips

In general, I love to cook. I enjoy cooking all types of food. I usually manage to impress those I cook for. However, I am having major problems with bread making (specifically the dough). I recently attempted to make sour dough rolls using starter and recipe I found on the internet, and just today I attempted to make cinnamon rolls (again using internet recipe). In both cases, I added the amount of flour called for during the final dough preparation step and found that I had a sticky gooey mess instead of a kneadable ball of dough. I have had this problem in the past with other recipes as well. The only thing I know to do is keep adding flour until I have a manageable ball of dough (in these 2 cases as much as 25% more flour than the recipe called for). My questions are...How to judge when enough flour as been added when making dough ? Does the humidity have an effect on making the dough (we average around 70% humidity and my kitchen is not climate controlled) ? In summary, any tips anyone can offer in helping to me to achieve my goal of becoming a competent bread baker will be much appreciated.