Standing Up For Myself

For my whole life I have had a very hard time with standing up for myself. Normally I would just sit and take everything that someone would give me and I would bend over backwards to keep them happy. I hated it when people were upset with me. I am the ultimate people-pleaser. I've been known for letting people walk right over me. Lately I have been tired of being such a pushover. I've been trying to find ways to assert myself better; to stick up for myself when I am being mistreated. Right now there are two individuals in my life who I am having a hard time sticking up for myself with. I'm finally to the point where I'm sick of letting things go on as they have been; so I've become more vocal with regards to the situation. Only, I'm not positive the way I'm going about it is the right way. But at least I'm getting to the point where enough is enough...and hopefully I'll learn soon of the proper way to stick up for myself. If anyone has any suggestions, I am all ears.