You would be more likely to get the answer that you are looking for if you told us what you wanted evaluated in these two websites. There are a number of ways in which one can evaluate a website. I will evaluate these websites in two ways.
First, I will evaluate the look and feel of the sites. Both of these sites are clearly made and maintained by professionals. They both have large pictures that change every so often and which are clearly the work of professional photographers. The pictures capture your interest and make you more likely to want to click on them to find more information. Both of the sites make it very easy to navigate further. Incidentally, both sites are clearly interested in soliciting money from visitors as both clearly show how one might donate to them.
Second, I will evaluate the messages sent by each site. The Brady site is a gun-control site. It supports laws that would make it harder for people to get guns, particularly guns with large magazines or fast rates of fire. The NRA site is a gun rights site. It also has some information about things like hunting, but it is mostly concerned with fighting against the sorts of laws that the Brady site would support. The Brady site is sending the message that our levels of gun violence are unacceptable and that our country deserves better. The NRA site is sending the message that gun rights are a fundamental American right that a minority of elites is trying to take away. There is no way to objectively evaluate the truth or validity of these messages.