I've been scrapbooking now for about 10 years sort of and on. I have a 5 year old Son and I want to do the same thing as you. I do journal in my scrapbook, cause the memories, feelings are important to write those down. Pictures are great and scrapbooking is great, however after you are gone, what you are left with is just pictures and maybe the date and info on the back of the picture. The cheaper photo albums or books, aren't always acid free and that's not a great thing if you are wanting your pictures to be around for a long time. If you do scrapbooking and journaling along with your pictures, than that in my opinion is much better for everyone, especially long term wise for preserving your photos, memories, feelings,etc...
Creative Memories really likes for you to journal. I have friend who sells Creative Memories and she has taught me to journal in my scrapbooks. You might want to try out a class or go to one of her crops! If you want more info on her and Creative Memories, I'll be glad to give you the info on it. I also have a catalog if you would like to look at it of Creative Memories, just let me know. I'm not wanting to pressure you or anything like that. Wanted you to know that this company is available and products are there to help you with your journaling/scrapbooking.
I journal, however I don't take up a whole page of the scrapbook. I tell about the event or things that are going on in the picture. I also describe my son's age and emotions/feelings,etc... I've only done my Son's baby book and journaled in the scrapbook. I've done a lot of other scrapbooks where I have journaled. What you may want to do is to balance the picture/pictures with the journaling. Journal part of the page and part of the pages be pictures. If you aren't using a lot of stickers,embellishments and that sort of thing, then yes you have more room for pictures and journaling. I would just say don't get too carried away with the journaling, if you want pictures in the album.
Yes, with kids you end up with tons of photos! I have a ton of my Son. However, you don't want to put all your pictures in your album or even picture albums. Of course, there is bad pictures and pictures that don't turn out very well or the sun is an issue,etc... You have to pick out the best pictures of your child and showcase them. I pick out my best pictures and put them in the scrapbook. I don't use all my child's pictures, cause that would be too expensive and buying too many scrapbooks. This is my opinion and what I would do. It is totally up to you and the way you want to do it. Buy another scrapbook or you can even make your own scrapbook, if you want to. You can use Cardstock and punch holes in it and put a rings around it, if you really want to save money. You could laminate it, if you want to protect it from the dust,etc.. That is the cheaper route of doing it that way. Scrapbooks do come on sale at Michael's, Jo-Ann's and Hobby Lobby. Also, they offer coupons- all these places do in the newspaper. Jo-Ann's sends out coupons to me, if you join their mailing list. You can buy a scrapbook on sale and use the coupon, possibly or buy it at regular price and use a coupon for 40% or more.
I'm in 2 meetup groups for scrapbooking, if you want to join us, you are welcome to join us in our groups. We meet for crops and that is when we do scrapbooking, going thru pictures, journaling, and etc.... We meet at a different house each time. If there is a cost to the meetup group it is $5 or $10, I believe at the most per year. The reason why there is a cost with meetup, is there is people actually working behind the scenes at meetup headquarters and they do the computer work, website maintenance and work hard to make meetup a better website for everyone. The Organizer has to pay so much per month to be a part of Meetup, as a meetup group. Anyway, the Organizer needs help in paying for that cost each month. That is why there is a cost to the group. It is a great way to meet other women who scrapbook/journal,etc... You also get other ideas from other women, which is neat. You learn new things and it is fun too! We usually have a pot luck and we each bring something to eat. This may or may not be for you. You may prefer to do journaling/scrapbooking on your own, which is ok too.
That's great that you are doing this for your Son. All Mom's should do this sort of thing for their child! Not everyone has the time or the creativity or the patience to do this type of journal or scrapbooking.
I wouldn't use regular paper in a composition type book, that's too casual looking, plus it won't preserve your precious photos many years from now. You should definitely use acid free paper. Acid free paper is important, because if you don't use it, then your pictures and paper will turn yellow over time. You don't want to happen! Make sure anything you buy that it is acid free or archival type free/safe for preserving photos,etc.... Definitely do it in a scrapbook or make your own type of scrapbook with the card stock.
I'm not sure how much journaling you are doing, but you might want to do a small paragraph or a couple of paragraphs each page. I usually do a paragraph and sometimes it is long paragraph. I use my stencils that have lines on it and a nice looking circle and oval shape around the lines. Creative Memories makes them and I have several of them and they are great. What you do is put the stencil down on the paper- some are really big, some are small and you trace the lines, or you can do both the lines and the circle around it. I have fancier one with a scrolly type of look that looks really pretty for journaling. This makes it so much easier for journaling! It looks pretty once it is done and not just plain old writing on the paper. Of course, you can use a ruler, if you really want to do that way. It is totally up to you and what you want to do with this.
Have fun and good luck!