Male Vs Female

Choosing between male and female dogs is sometimes a personal preference. However, there are some traits common in females and other traits common in male dogs. It is always good to determine which sex would fit in best with your home situation if you already have another female or male dog.
Some traits common with a female are:
Females like to be in control of some situations, they seek their owner in times of affection but will tend to move away when they have had enough some females tend to be self soothers and like to be alone establishing dominance. Females tend to be more independent.
In the case where you have more than one female or dog, females will tend to become stubborn and not want to change, they establish a "alpha" trait, which can be and should be controlled quickly.
Females can be less affectionate and friendly than male dogs. It can sometimes be notice in the puppy stage. Females become more reserved with age.
A changes in Mood or Behaviour may occur if you do not spay your female when they are coming into their heat cycle they can be aggressive and dominate in nature for a week. Then the heat cycle will start and they become very protective of themselves, finally changing to a very clingy nature during the end of their cycle, all of which can last for 21 days more or less. This can happen twice a year if they are not spayed. Typically the moods will disappear after being spayed and they become a very soft natured female in most cases. A female that is given the option to go thru a cycle prior to spay sometimes may become much more reserved and settled in their personality, with some breeds this is very evident.
Some traits common with a Male Dog are:
Male dogs tend to be more affectionate towards their owners, they tend to be fun-loving and outgoing during their lifetime and maintain this trait throughout their life time. They are much more exuberant.
Males are much more food motivated and can make training much easier with a male and learn tricks and desired behaviours much quicker than females.
Males tend to be more focused on their owners, willingness to please and to be a constant companion and very eager to please their owners.
A male may tend to be aggressive in nature when a female in heat is near, they will be focused and establish dominance over that female very quickly. They tend to establish a marking pattern in the home and yard area if another male is present in the home and if or when another male comes to visit, this can cause some concerns for furniture and wet feet if control of their environment is not monitor, this is a very natural behaviour for all animals and should not be viewed negatively or with anger. If you male is neutered they tend not to be aggressive around females and become very settled in their homes. The marking of territory is a trait that is inbred in them and will continue as long as another male is in his territory and is a natural response to protecting his home.
IF you choose not to neuter you male you run the risk of a very aggressive nature when going out, going for walks, lack of control when a female in heat is in the area and their need to breed which is again an natural trait for all male animals.
The following are general tips for selecting the gender of a second dog:
If you already have a male or female in the home the opposite sex is usually a better choice as long as they are both spayed and neutered to alleviate some of the above traits which are natural in animals. A male is more likely to be more accepting of a female and have fewer dominance concerns.
You can also establish a very normal, safe and calm environment if you have two from the same sex if things are monitored and controlled, it is best to purchase one Sex and bring the second one in at least a year later, this way the first puppy will be settled and learn the required behaviours of your home. Females tend to bond to each other easier and quicker, males do take some training and control for the dominance nature, especially with larger breeds. Two of the same sex that are brought in the same time tend to bond to each other and not to the family which establishes a "alpha" between themselves and not a bonding to the family which is the purpose of buying a family pet to create a bond with the family first.
Also when purchasing a second dog, always consider the first dog in your home, if a breeder is educated in a second pet homing situation they will help with this process by giving a blanket with the new puppies scent on it for the transition home prior to the new puppy coming home. Also you should provide the breeder with a blanket or t-shirt that your current dog has scented and then trade these during the growth of your new puppy till you bring that puppy home.
When introducing your new puppy to the current puppy always take them to a neutral site first and monitor the interaction as it happens. Then proceed to your home and let your current dog bring the new puppy in, DO NOT carry your new puppy in and put him down and hope for the best. This process must be taken very seriously and careful attention to the current dog must be foremost on your time and care. They new puppy will adjust but if not handled properly the current puppy may not.
If you find a good breeder all these points and information should be discussed and you should be given opportune time to consider the sex of you puppy and how to handle which ever puppy you decide and how to introduce a new puppy to a home and if you have an existing puppy care and attention should be considered with that puppy first.